JP6382254B2 - Communication device for multiple group communication - Google Patents

Description

Related applications
[0001] This application is a US Provisional Patent Application No. 61 / 494,626 entitled "COMMUNICATION DEVICES FOR MULTIPLE GROUP COMMUNICATIONS" filed June 8, 2011, which is incorporated herein by reference in its entirety. Claim its priority.

  [0002] The present disclosure relates generally to communication systems. More particularly, the present disclosure relates to a communication device for multiple group communication.

  [0003] Communication systems are widely deployed to provide various types of communication content such as data, voice, and video. These systems can support simultaneous communication of multiple communication devices (eg, wireless communication devices, access terminals, etc.) with one or more other communication devices (eg, base stations, access points, etc.). Multiple access systems.

  [0004] The use of communication devices has increased dramatically over the past few years. Communication devices often provide access to networks such as, for example, a local area network (LAN) or the Internet. Other communication devices (eg, access terminals, laptop computers, smartphones, media players, gaming devices, etc.) may communicate wirelessly with communication devices that provide network access. Some communication devices comply with several industry standards, such as the American Institute of Electrical and Electronics Engineers (IEEE) 802.11 (eg, wireless fidelity or “Wi-Fi”) standard. Communication device users, for example, often connect to wireless networks using such communication devices.

  [0005] Since the use of communication devices is increasing, there is a demand for improvement in communication device capacity. Systems and methods that improve communication device capacity may be beneficial.

  [0006] The systems and methods disclosed herein may enable multi-user multiple-input multiple-output (MU-MIMO) to multiple groups. According to the systems and methods disclosed herein, for example, the number of downlink wireless communication devices (eg, clients) is divided into no more than four groups in the case of resolvable LTFs (resolvable LTFs). In the case of an unresolvable LTF (unresolvable LTF), it can be divided into eight groups or less. For example, a base station (eg, access point) may simultaneously beamform into multiple groups such that the omnidirectional part of the preamble is beamformed. In this way, each group can only “see” the signaling related to that group. Further, wireless communication devices (eg, clients) in one group may receive reduced or minimal interference from transmissions to another group. Within a group, a base station (eg, access) so that wireless communication devices (eg, clients) within the group receive signals intended for all wireless communication devices (eg, clients) in the same group. Point) is a resolvable LTF and some form of eigenmode selection (eg, minimum mean-square error (MMSE) eigenmode selection (MMSE-ES) or multi-user eigenmode transmission) (MET: multi-user eigenmode transmission).

  [0007] A base station for communicating with a plurality of groups of wireless communication devices is disclosed. The base station includes a processor and instructions stored in memory in electronic communication with the processor. The base station determines the number of wireless communication devices. The base station is also divided into groups of the above number of wireless communication devices. The base station further determines a precoding matrix for each group. Further, the base station transmits the beamformed signal to each group using the precoding matrix for each group. The base station may also receive channel information. The base station may also use media access control protection.

  [0008] Determining a precoding matrix for each group may be performed to beamform the omnidirectional portion of the preamble. A precoding matrix for the current group may be applied to the first part of the preamble, and the base station may also apply a second precoding matrix for the current group applied to the second part of the preamble. Can be judged.

  [0009] Determining a precoding matrix for each group may also include determining a group channel for the current group and determining a complement group channel. Determining the precoding matrix for each group may also include determining between complement group channel null spaces. Determining the precoding matrix for each group further includes determining a client channel for each wireless communication device in the current group, and a client channel and complement group channel null space for each wireless communication device. Determining a precoding matrix for the current group based on.

[0010] Determining the complement group channel null space

Can be achieved according to.

May be a complement group channel. U '

Of the left singular vector. S '

Of singular values. V 'is

Of the right singular vector. svd () may be a singular value decomposition function. The complement group channel null space V _n may include the last N _tx − (N _rxt −N _rxk ) columns of V ′. N _tx may be the number of base station transmitters. N _rxt may be the total number of wireless communication device receivers and N _rxk may be the total number of receivers in group k.

[0011] Determining the precoding matrix for the current group consists of the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation

And can be achieved according to: H _mk may be a client channel. V _n may be a complement group channel null space. U _m may include the left singular vector of H _mk V _n . S _m can be a singular value of H _mk V _n . V _m may include the right singular vector of H _mk V _n . svd () may be a singular value decomposition function. W _k may be a precoding matrix for group k and m may be an index number.

[0012] Determining the precoding matrix for the current group consists of the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation Z (:, (m−1) N _ssmk +1. : _M * N _ssmk ) = V _m (:, 1: N _ssmk ) S _m (1: N _ssmk , 1: N _ssmk ) and formula

And can be achieved according to: H _mk may be a client channel. V _n may be a complement group channel null space. U _m may include the left singular vector of H _mk V _n . S _m can be a singular value of H _mk V _n . V _m may include the right singular vector of H _mk V _n . svd () may be a singular value decomposition function. N _ssmk may be the number of spatial streams of wireless communication device m in group k. Z may be a matrix with the selected eigenmode. The superscript ^H may indicate a conjugate transpose. I can be an identity matrix. SNR _k may be an estimate of the average signal to noise ratio (SNR) in the downlink for group k. W _km may be a precoding matrix.

[0013] Determining the precoding matrix for the current group consists of the expression [U _m , S _m , V _m ] = svd (H _mk V _n ) and the expression D _m = V _m (:, 1: N _ssmk ) S _m (1: N _ssmk , 1: N _ssmk ) and the formula

And the formula [U _mz , S _mz , V _mz ] = svd (Z)

And the expression

And can be achieved according to: H _mk may be a client channel. V _n may be a complement group channel null space. U _m may include the left singular vector of H _mk V _n . S _m can be a singular value of H _mk V _n . V _m may include the right singular vector of H _mk V _n . svd () may be a singular value decomposition function. N _ssmk may be the number of spatial streams of wireless communication device m in group k. D _m may be a steering vector for the wireless communication device m. Z may be a matrix of steering vectors to all wireless communication devices in group k other than wireless communication device m. The superscript ^H may indicate a conjugate transpose. N _ck may be the number of wireless communication devices in group k. U _mz may contain the left singular vector of Z. S _mz can be a singular value of Z. V _mz may include the right singular vector of Z. U is

Of the left singular vector. S is

Can be a singular value. V is

Of the right singular vector. N _ssk may be the number of spatial streams for group k.

_Can be an identity matrix with N _ssmk rows and columns. SNR _k may be an estimate of the average signal to noise ratio (SNR) in the downlink for group k. W _km may be a precoding matrix.

  [0014] The base station may further send multiple channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests. The base station may also receive multiple channel state information messages from the same wireless communication device and combine multiple channel state information messages.

[0015] Determining the precoding matrix for the current group is _Hck

Can be achieved by setting H _ck may be a channel for wireless communication device c in group k.

May be a beamforming matrix for wireless communication device c. N _ssck may be the number of spatial streams for wireless communication device c in group k. The superscript ^H may indicate a conjugate transpose.

[0016] Determining the precoding matrix for the current group is _Hck

Can be achieved by setting H _ck may be a channel for wireless communication device c in group k.

May be a beamforming matrix for wireless communication device c.

May be a singular value for the wireless communication device c. N _ssck may be the number of spatial streams for wireless communication device c in group k. The superscript ^H may indicate a conjugate transpose.

  [0017] A wireless communication device for receiving a group signal is also disclosed. The wireless communication device includes a processor and instructions stored in memory in electronic communication with the processor. The wireless communication device receives the group signal. The group signal includes information about two or more wireless communication devices. The wireless communication device also uses spatial filtering to recover data about the wireless communication device from the group signal.

  [0018] The wireless communication device may also receive multiple channel information requests. The wireless communication device may further determine channel information for each of the channel information requests. Further, the wireless communication device may send channel information. The wireless communication device may also receive a clear to send (CTS) signal and wait for a predetermined amount of time before transmitting the signal.

[0019] The data is an expression

And can be restored using spatial filtering. U _c may be U _m including the left singular vector of H _mk V _n for wireless communication device m = c. H _mk may be a client channel. V _n may be a complement group channel null space.

_{Can be} a singular value of _Hck . H _ck may be a channel for wireless communication device c. N _ssck may be the number of spatial streams for wireless communication device c in group k.

_May contain the left singular vector of Hck. The superscript ^H may indicate a conjugate transpose.

[0020] The data is an expression

And can be restored using spatial filtering. U _c may be U _m including the left singular vector of H _mk V _n for wireless communication device m = c. H _mk may be a client channel. V _n may be a complement group channel null space.

_May contain the left singular vector of Hck. H _ck may be a channel for wireless communication device c. The superscript ^H may indicate a conjugate transpose.

  [0021] A method for a base station to communicate with multiple groups of wireless communication devices is also disclosed. The method includes determining the number of wireless communication devices. The method also includes dividing into the number of groups of wireless communication devices. The method further includes determining a precoding matrix for each group. The method further includes transmitting the beamformed signal to each group using the precoding matrix for each group.

[0022] A method for a wireless communication device to receive a group signal is also disclosed.
The method includes receiving a group signal that includes information about two or more wireless communication devices. The method also includes recovering data about the wireless communication device from the group signal using spatial filtering.

  [0023] A computer program product for communicating with a plurality of groups of wireless communication devices is also disclosed. The computer program product includes a non-transitory tangible computer readable medium having instructions. The instructions include code for causing the base station to determine the number of wireless communication devices. The instructions also include code for causing the base station to divide the number of wireless communication devices into groups. The instructions further include code for causing the base station to determine a precoding matrix for each group. The instructions further include code for causing the base station to transmit the beamformed signal to each group using the precoding matrix for each group.

  [0024] A computer program product for receiving a group signal is also disclosed. The computer program product includes a non-transitory tangible computer readable medium having instructions. The instructions include code for causing the wireless communication device to receive a group signal. The group signal includes information about two or more wireless communication devices. The instructions also include code for causing the wireless communication device to recover data about the wireless communication device from the group signal using spatial filtering.

  [0025] An apparatus for communicating with a plurality of groups of wireless communication devices is also disclosed. The apparatus includes means for determining the number of wireless communication devices. The apparatus also includes means for dividing the group of the number of wireless communication devices. The apparatus further includes means for determining a precoding matrix for each group. The apparatus further includes means for transmitting the beamformed signal to each group using the precoding matrix for each group.

  [0026] An apparatus for receiving a group signal is also disclosed. The apparatus includes means for receiving a group signal. The group signal includes information about two or more wireless communication devices. The apparatus also includes means for recovering data about the wireless communication device from the group signal using spatial filtering.

[0027] FIG. 7 is a block diagram illustrating one configuration of a transmitting communication device and one or more receiving communication devices in which systems and methods for multiple group communications may be implemented. [0028] FIG. 9 is a block diagram illustrating an example of beamforming into multiple groups of wireless communication devices in accordance with the systems and methods disclosed herein. [0029] FIG. 7 is a flow diagram illustrating one configuration of a method for group communication. [0030] FIG. 10 is a diagram illustrating an example of a communication frame that may be used in accordance with the systems and methods disclosed herein. [0031] FIG. 10 illustrates another example of a communication frame that may be used in accordance with the systems and methods disclosed herein. [0032] FIG. 7 is a flowchart showing a more specific configuration of a method for multiple group communication. [0033] FIG. 9 is a flow diagram illustrating another more specific configuration of a method for multiple group communication. [0034] FIG. 9 is a flow diagram illustrating another more specific configuration of a method for multiple group communication. [0035] FIG. 9 is a flow diagram illustrating one configuration of a method for receiving group communications. [0036] FIG. 10 is a block diagram illustrating a configuration of an access point and an access terminal in which systems and methods for multiple group communications may be implemented. [0037] FIG. 7 is a block diagram of a base station that may be used in a multiple-input multiple-output (MIMO) system. [0038] FIG. 7 illustrates some components that may be included within a transmitting communication device, a base station, and / or an access point. [0039] FIG. 7 shows some components that may be included in a receiving communication device, a wireless communication device and / or an access terminal.

  [0040] Examples of communication devices include cellular telephone base stations or nodes, access points, wireless gateways and wireless routers. The communication device may include an American Institute of Electrical and Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n, and / or 802.11ac (eg, wireless fidelity or “Wi-Fi”) standard, etc. It can operate according to several industry standards. Other examples of standards that a communications device may conform to include IEEE 802.16 (eg, Worldwide Interoperability for Microwave Access or “WiMAX”), Third Generation Partnership Project (3GPP (registered trademark) 3GPP (registered trademark)) (For example, a communication device may be referred to as a Node B, an evolved Node B (eNB), etc.). Some of the systems and methods disclosed herein may be described with respect to one or more standards, as these systems and methods may be applicable to many systems and / or standards. The scope of the disclosure should not be limited.

  [0041] Some communication devices (eg, access terminals, client devices, client stations, etc.) may communicate wirelessly with other communication devices. Some communication devices (eg, wireless communication devices) are mobile devices, mobile stations, subscriber stations, clients, client stations, user equipment (UE), remote stations, access terminals, mobile terminals, terminals, user terminals, subscriptions Sometimes called a person unit. Further examples of communication devices include laptops or desktop computers, cellular phones, smartphones, wireless modems, electronic readers, tablet devices, gaming systems, and the like. Some of these communication devices may operate according to one or more industry standards as described above. Thus, the general term “communication device” refers to communication devices (eg, access terminals, user equipment (UEs), remote terminals, access points, base stations, Node Bs, described with different names according to industry standards. Evolved Node B (eNB), etc.).

  [0042] Some communication devices may be capable of accessing a communication network. Examples of communication networks include, but are not limited to, telephone networks (eg, “land-line” networks such as the public switched telephone network (PSTN) or cellular phone networks), the Internet, local area networks (LANs), There are wide area networks (WAN), metropolitan area networks (MAN), and the like.

  [0043] The systems and methods disclosed herein describe downlink multi-user multiple-input multiple-output (MU-MIMO) to multiple groups. For example, IEEE 802.11ac is in the process of standardizing MU-MIMO into groups of up to four wireless communication devices. Some proposals for downlink MU-MIMO limit the number of wireless communication devices (eg, clients) in downlink transmission to four. Limiting the number of wireless communication devices to four limits the gain of downlink MU-MIMO. However, the systems and methods disclosed herein allow communication devices (eg, base stations or access points) with sufficient transmit antennas to have more wireless communication devices (eg, clients) than would be foreseen by these proposals. ) Proves how downlink MU-MIMO packets can be transmitted. In accordance with the systems and methods disclosed herein, a base station (e.g., access point) allows a wireless communication device (e.g., at the same time) (e.g., at the same time) to reduce or minimize interference between groups. (E.g., client, access terminal, etc.). Within each group, the base station may use some form of eigenmode transmission so that the wireless communication device antenna may receive signals intended for each client in the group. In accordance with the systems and methods disclosed herein, the total number of wireless communication devices may be limited only by the number or amount of antennas at the base station (eg, access point). This can be beneficial by increasing the throughput.

[0044] In one configuration of the systems and methods disclosed herein, 802.11ac frames or packets may be used. A frame may include a preamble and data.
In accordance with the systems and methods disclosed herein, a preamble may include one or more fields that are transmitted in a (generally or conventional) omni-directional manner.

  [0045] In a first alternative, the preamble includes a legacy short training field (L-STF), a legacy long training field (L-LTF), and a legacy signal field (L SIG: legacy signal field, first very high throughput signal or symbol A (VHT-SIG-A1), and second very high throughput signal or symbol A (VHT-SIG-A2) ), A very high throughput short training field (VHT-STF), one or more ultra high throughput long training fields ((one or more) VHT-LTF), and an ultra high throughput signal B (VHT-SIG). -B). In this first alternative, L-STF, L-LTF, L-SIG, VHT-SIG-A1 and VHT-SIG-A2 may be (generally) transmitted in an omnidirectional fashion.

  [0046] In a second alternative, the preamble includes L-STF, L-LTF, L-SIG, VHT-SIG-A1, VHT-SIG-A2, and a third ultra-high throughput field signal. A (VHT-SIG-A3), VHT-STF, and one or more VHT-LTFs. In this second alternative, L-STF, L-LTF, L-SIG, VHT-SIG-A1, VHT-SIG-A2, and VHT-SIG-A3 may generally be transmitted in an omnidirectional manner.

  [0047] Both alternative preambles are used for 802.11a-based legacy deferral and to carry 802.11ac information such as downlink MU-MIMO packets and bandwidth length. Start with the first part or the omnidirectional part to get. A second preamble alternative may include all 802.11ac signaling information in the omni-directional part, including a modulation and coding scheme (MCS) per downlink wireless communication device or client. The first preamble alternative may include some client specific signaling such as MCS in the steered VHT-SIG-B symbol.

  [0048] Both preamble alternatives may have the possibility to use a resolvable long training field (LTF) or an unresolvable LTF (unresolvable LTF). For resolvable LTFs, for example, the number of LTF symbols per wireless communication device (eg, client) is equal to or greater than the total number of spatial streams for all wireless communication devices (eg, clients). For unresolvable LTFs, for example, the number of LTF symbols per wireless communication device (eg, client) is only equal to or greater than the number of spatial streams per wireless communication device (eg, client). .

  [0049] For resolvable LTFs, the number of wireless communication devices (eg, clients) in a downlink MU-MIMO packet may be limited to four in both preamble alternatives. For unresolvable LTFs, the number of wireless communication devices (eg, clients) in the downlink MU-MIMO packet may be limited to 8 in the first preamble alternative and 4 in the second preamble alternative. Can be limited to one. For both preamble alternatives, the total number of streams for all downlink wireless communication devices (eg, clients) may not exceed eight.

  [0050] The systems and methods disclosed herein may enable MU-MIMO to multiple groups. In accordance with the systems and methods disclosed herein, for example, the number of downlink wireless communication devices (eg, clients) is divided or resolved into no more than four groups for resolvable LTFs. In case of impossible LTF, it can be divided into 8 or less groups. For example, a base station (eg, access point) may simultaneously beamform into multiple groups such that the omnidirectional portion of the preamble is beamformed. In this way, each group may “see” only the signaling related to that group. Further, wireless communication devices (eg, clients) in one group may receive reduced or minimal interference from transmissions to another group. Within a group, a base station (eg, access) so that wireless communication devices (eg, clients) within the group receive signals intended for all wireless communication devices (eg, clients) in the same group. Point) may use a resolvable LTF and some form of eigenmode selection (eg, minimum mean square error (MMSE) eigenmode selection (MMSE-ES) or multi-user eigenmode transmission (MET)). .

[0051] For convenience and descriptive clarity, a number of abbreviations may be used as follows. N _G is the number of groups. N _rxt is the total number of wireless communication device (eg, client) receivers. N _tx is the number of base station (eg, access point) transmitters. N _rxk is the total number of receivers in group k. N _rxmk is the number of wireless communication device (eg, client) m receivers in group k. N _ssmk is the number of spatial streams of wireless communication devices (eg, clients) m in group k. H represents a MU-MIMO downlink channel of size or dimension N _rxt × N _tx . W _k is the beamforming or precoding matrix for group k of size or dimension N _tk × N _ssk . SNR _k is an estimate of the average signal to noise ratio (SNR) in the downlink for group k. N _ck is the number of wireless communication devices (eg, clients) in group k. W (:, x: y) is a submatrix of W containing all the rows and columns from x to y.

[0052] The systems and methods disclosed herein may use multi-group block diagonalization. In one configuration, the precoding matrix W _k for group k up to VHT-SIG-A (eg, the omni-directionally transmitted portion) and for the first portion of the preamble that includes VHT-SIG-A. Can be calculated as shown in list (1).

  In list (1), svd () may be a singular value decomposition function.

[0053] In one configuration, the precoding matrix W _k for group k for the second part of the packet or frame starting from VHT-STF may be as shown in list (2). For example, the technique shown in list (2) below may use the least mean square error eigenmode selection within the group.

  [0054] Note that the only difference in precoding for the first part of the preamble is that no attempt is made to cancel multi-user interference within the group. This is not necessary because all data is equal for all wireless communication devices (eg, clients) in the same group for the first part of the preamble (eg, up to VHT-STF).

  [0055] Alternatively, the first part of the preamble may be precoded equally to the second part. For example, a wireless communication device (eg, a client) cannot distinguish between spatial streams before receiving subsequent portions (eg, VHT-LTF, etc.), but interference between spatial streams in the group can be canceled. . If a wireless communication device (eg, client) has more than one spatial stream, a single stream of the first portion of the preamble can be copied to all stream inputs of that wireless communication device (eg, client). . The first portion of the preamble can be further decoded by all wireless communication devices (eg, clients) since every spatial stream contains the same information. This approach may actually be preferable because it requires only a single precoding matrix per packet instead of two different precoding matrices.

[0056] Another configuration of the systems and methods disclosed herein may use multi-group block diagonalization with multi-user eigenmode transmission (MET). As mentioned above, previous algorithms applied the least mean square error eigenmode selection within the group. One alternative is to use multi-user eigenmode transmission (MET) within the group. Note that the least mean square error eigenmode selection is simpler and may have better performance than this alternative approach. This alternative approach using multi-user eigenmode transmission (MET) is shown in list (3).

  [0057] In one configuration, the systems and methods disclosed herein may use signaling as follows. Block diagonalization may be used on the first part of the preamble (eg, up to and including VHT-SIG-A). The same data content can be used in the L-SIG for all groups so that any legacy 802.11a / n device can accurately yield for the duration of the downlink MU-MIMO packet or frame. Since the L-SIG is beamformed into two or more different groups, there is sufficient power for wireless communication devices (eg, stations) outside these groups to correctly decode the deferral length. There is a possibility that L-SIG will not be received. Media access control (MAC) protection may be used to prevent collisions from these wireless communication devices (eg, stations). For example, a separate transmit ready (CTS) signal may be sent before the downlink MU-MIMO packet.

  [0058] In one configuration of the systems and methods disclosed herein, channel state information (CSI) feedback may be used. In 802.11ac, CSI feedback may be limited to 8 antennas. A base station (eg, access point or AP) with 8 or more antennas may need to send multiple feedback requests to get the channel on all of its antennas.

[0059] For up to 15 base station (eg, AP) transmit antennas, an example procedure using channel state information is described as follows. The base station may send a channel state information (CSI) request twice for each wireless communication device (eg, client) and transmits from only 8 antennas each time (eg, all other antennas do not transmit anything). Different channel state information (CSI) requests to the same wireless communication device (eg, client) may need to include at least one common transmit antenna. This may be required to remove the phase shift that occurs between two different channel state information feedbacks. In one configuration, multiple channel state information messages (eg, CSI feedback) may be received (this is described below).
Different channel state information feedback can be combined by normalizing all channels with the values for the common antenna so that the channel values for the common transmit antenna match.

  [0060] For 15 or more antennas, the above procedure may be extended to 3 or more channel state information (CSI) requests, all with at least one common reference antenna. The above procedure can also be used in a group of four antennas such that existing 802.11n channel state information feedback limited to a maximum of four transmitters can be used.

[0061] One configuration of flexible multi-group block diagonalization may be used in accordance with the systems and methods disclosed herein. In this configuration, for a wireless communication device (eg, client) c in group k, the base station (eg, AP) obtains only the beamforming matrix and average signal-to-noise ratio (SNR) per stream, eg, The wireless communication device (eg, client) c is

Through beamforming matrix

, But other (one or more) wireless communication devices (eg, clients) have fed back channel state information H _mk . H _mk is the client channel,

_Contains the left singular vector of Hck,

Is the singular value of H _ck

_Contains the right singular vector of _Hck .

Is the beamforming matrix for wireless communication device c, and N _ssck is the number of spatial streams for wireless communication device c in group k. In this case, the base station (e.g., AP) is an H _ck

(As well as the corresponding part in H _k ). Note that the matrix herein may indicate a wireless communication device using the subscript c. The rest of the processing can be performed in the same way as the previously described multi-group block diagonalization procedure shown in list (1), list (2) and / or list (3) above. For example, assuming that the procedure shown in list (1) above is used, the wireless communication device (eg, client) c is at its receiver to recover its data shown in equation (1). Dedicated spatial filtering may be applied.

In equation (1), U _c is given in list (1) for the wireless communication device (eg, client) m = c. Alternatively, depending on the MU-MIMO technique used, the receiver may perform any other type of MIMO processing or interference suppression (eg, assuming proper channel estimation is performed).

[0062] Another configuration of flexible multi-group block diagonalization may be used in accordance with the systems and methods disclosed herein. In this configuration, for a wireless communication device (eg, client) c in group k, the base station (eg, AP) obtains only the beamforming matrix and singular values, for example, the wireless communication device (eg, client) c ,

Through beamforming matrix

And singular values

However, it is assumed that other wireless communication devices (eg, clients) have fed back the channel state information H _mk . In this case, the base station (e.g., AP) is an H _ck

(As well as the corresponding part in H _k ). The rest of the processing can be performed in the same way as the previously described multi-group block diagonalization procedure shown in list (1), list (2) and / or list (3) above. For example, assuming that the procedure shown in list (1) above is used, the wireless communication device (eg, client) c is at its receiver to recover its data as shown in equation (2). Dedicated spatial filtering may be applied.

In equation (2), U _c is given in list (1) for the wireless communication device (eg, client) m = c. Alternatively, depending on the MU-MIMO technique used, the receiver may perform any other type of MIMO processing or interference suppression (eg, assuming proper channel estimation is performed).

  Next, various configurations will be described with reference to the drawings. Similar reference numbers may indicate functionally similar elements. The systems and methods generally described herein and illustrated in the figures can be configured and designed in a wide variety of different configurations. Accordingly, the following more detailed description of several configurations depicted in the figures is not intended to limit the scope of the claims, but is merely representative of systems and methods.

[0064] FIG. 1 is a block diagram illustrating one configuration of a transmitting communication device 102 and one or more receiving communication devices 142 in which systems and methods for multiple group communications may be implemented. Examples of the transmitting communication device 102 include a base station and an access point. Examples of receiving communication device (s) 142 include wireless communication devices, access terminals, stations, and the like. The transmitting communication device 102 may include an encoder 106 having an input for receiving payload data 104 and / or overhead data 116 to be transmitted to one or more receiving communication devices 142. Payload data 104 may include voice, video, audio and / or other data.
Overhead data 116 includes control information such as information specifying the data rate, modulation and coding scheme (MCS), channel bandwidth, frame length, defer period, media access control (MAC) information (eg, transmittable) (CTS) information), channel information requests (eg, channel state information (CSI) requests), and the like. Encoder 106 may encode data 104, 116 for other known encodings for use with forward error correction (FEC), encryption, packetization, and / or wireless transmission.

  [0065] The constellation mapper 110 maps the data provided by the encoder 106 to the constellation. For example, the constellation mapper 110 may use a modulation scheme such as binary phase shift keying (BPSK), quadrature amplitude modulation (QAM). If quadrature amplitude modulation (QAM) is used, for example, constellation mapper 110 may provide 2 bits per spatial stream 138, per subcarrier 140, and per symbol period. Further, the constellation mapper 110 may output a 16QAM constellation signal for each spatial stream 138, for each data subcarrier 140, and for each symbol period. Other modulations such as 64QAM may be used, which would result in a consumption of 6 bits per spatial stream 138, per data subcarrier 140, per symbol period. Other variations are possible.

  [0066] The output of constellation mapper 110 is provided to a spatio-temporal frequency mapper 108 that maps the data onto the spatial-time-frequency (STF) dimension of the transmitter. A dimension represents various constructs or resources that allow data to be allocated. A given bit or set of bits (eg, a grouping of bits corresponding to a constellation point, a set of bits, etc.) may be mapped to a specific location between dimensions. In general, bits and / or signals that are mapped to different places between dimensions are expected to be distinguishable at one or more receiving communication devices 142 with a certain probability. Sent from In one configuration, space-time frequency mapper 108 may perform space-time block coding (STBC).

  [0067] One or more spatial streams 138 may be transmitted from the transmitting communication device 102 such that transmissions on different spatial streams 138 may be distinguishable at the receiver (with some probability). For example, bits mapped to one spatial dimension are transmitted as one spatial stream 138. The spatial stream 138 may have its own antenna 132 spatially distinct from the other antennas 132, its own orthogonal superposition on multiple spatially separated antennas 132, its own polarization, etc. Can be sent on. Many techniques for spatial stream 138 separation are known (eg, with separation of antennas 132 in space, or other techniques that would allow those signals to be identified at the receiver). And can be used.

[0068] In the example shown in FIG. 1, there are one or more spatial streams 138 that are transmitted using the same or different (eg, one or more) antennas 132a-n.
In some cases, only one spatial stream 138 may be available for deactivation of one or more other spatial streams 138.

  [0069] When the transmitting communication device 102 uses multiple frequency subcarriers 140, the space-time frequency mapper 108 maps some bits to one frequency subcarrier 140 and other bits to another frequency subcarrier 140. There are multiple values for the frequency dimension so that they can be mapped to Other frequency subcarriers 140 may be reserved as guard bands, pilot tone subcarriers, etc. that do not carry (or do not always carry) data 104, 116. For example, there may be one or more data subcarriers 140 and one or more pilot subcarriers 140. Note that in some cases or configurations, not all subcarriers 140 may be immediately excited. For example, some tones may not be excited to allow filtering. In one configuration, the transmitting communication device 102 may utilize orthogonal frequency division multiplexing (OFDM) for transmission of multiple subcarriers 140. For example, the space-time frequency mapper 108 may map the (encoded) data 104, 116 to time and / or frequency resources according to the multiplexing scheme used.

[0070] The time dimension refers to the symbol period. Different bits may be allocated for different symbol periods. If there are multiple spatial streams 138, multiple subcarriers 140, and multiple symbol periods, transmissions during one symbol period may be referred to as "OFDM (Orthogonal Frequency Division Multiplexing) MIMO (Multiple Input Multiple Output) symbols". is there. By simply multiplying the number of bits per symbol (eg, log ₂ of the number of constellations used) × the number of spatial streams 138 × the number of data subcarriers 140, divided by the length of the symbol period, A transmission rate for the encoded data may be determined.

[0071] In this manner, the space-time frequency mapper 108 may map bits (or other units of input data) to one or more spatial streams 138, data subcarriers 140, and / or symbol periods. Separate spatial streams 138 may be generated and / or transmitted using separate paths. In some implementations, these paths are implemented using separate hardware, while in other implementations the path hardware is reused for more than one spatial stream 138, Or, path logic is implemented in software executing for one or more spatial streams 138.
More specifically, each of the elements shown in transmitting communication device 102 may be implemented as a single block / module or as multiple blocks / modules. For example, the transmitter radio frequency block 126 element (s) may be as a single block / module or as multiple parallel blocks / modules corresponding to each antenna 132a-n (eg, each spatial stream 138). Can be implemented. As used herein, the term “block / module” and variations thereof may indicate that a particular element or component may be implemented in hardware, software, or a combination of both.

  [0072] The transmitting communication device 102 may include a pilot generator block / module 130. Pilot generator block / module 130 may generate a pilot sequence. A pilot sequence may be a group of pilot symbols. In one configuration, for example, values in a pilot sequence may be represented by a signal having a particular phase, amplitude and / or frequency. For example, “1” may indicate a pilot symbol with a particular phase and / or amplitude, while “−1” has a different (eg, opposite or inverse) phase and / or amplitude. Pilot symbols may be indicated.

[0073] The transmitting communication device 102 may include a pseudo-random noise generator 128 in some configurations. The pseudo-random noise generator 128 may generate a pseudo-random noise sequence or signal (eg, value) that is used to scramble the pilot sequence.
For example, the pilot sequence for consecutive OFDM symbols may be multiplied by consecutive numbers from the pseudo-random noise sequence, thereby scrambling the pilot sequence for each OFDM symbol. Once the pilot sequence is sent to receiving communication device 142, the received pilot sequence may be descrambled by pilot processor 148.

  [0074] The output (s) of the spatio-temporal frequency mapper 108 may be spread across frequency and / or spatial dimensions. Pilot insertion block / module 112 inserts pilot tones into pilot tone subcarrier 140. For example, the pilot sequence may be mapped to subcarrier 140 at a particular index. For example, pilot symbols from a pilot sequence may be mapped to subcarriers 140 interspersed with data subcarriers 140 and / or other subcarriers 140. In other words, the pilot sequence or signal can be combined with the data sequence or signal. In some configurations, one or more direct current (DC) tones may be centered at index 0.

  [0075] Data and / or pilot signals are provided to an inverse discrete Fourier transform (IDFT) block / module 120. An Inverse Discrete Fourier Transform (IDFT) block / module 120 converts the frequency signal of the data 104, 116 and the inserted pilot tones into a time domain signal and / or symbol period representing a signal on the spatial stream 138. Convert to region sample. In one configuration, for example, IDFT block / module 120 may perform a 256-point inverse fast Fourier transform (IFFT).

  The time domain signal is provided to formatter 122. A formatter (eg, one or more formatting blocks / modules) 122 takes the output of an inverse discrete Fourier transform (IDFT) block / module 120 and converts it from parallel signals to serial (P / S) and cyclic A cyclical prefix may be added and / or guard interval window processing or the like may be performed.

  [0077] The output of the formatter 122 may be provided to a digital-to-analog converter (DAC) 124. A digital to analog converter (DAC) 124 may convert the formatter 122 output from one or more digital signals to one or more analog signals. A digital to analog converter (DAC) 124 may provide the analog signal (s) to one or more transmitter radio frequency (TX RF) blocks 126.

  [0078] One or more transmitter radio frequency blocks 126 may be coupled to or include a power amplifier. The power amplifier may amplify the analog signal (s) for transmission. One or more transmitter radio frequency blocks 126 may output a radio frequency (RF) signal to one or more antennas 132a-n for reception by one or more receiving communication devices 142. The input data 104, 116 is transmitted to the encoder 106 via a wireless medium appropriately configured.

  [0079] The transmitting communication device 102 may also include one or more receiver radio frequency blocks / modules 134. One or more receiver radio frequency blocks / modules 134 may be used to receive signals from one or more receiving communication devices 142. For example, the transmitting communication device 102 may transmit pilot and / or training symbols to one or more receiving communication devices 142. One or more receiving communication devices 142 may use pilot and / or training symbols to estimate the channel. The one or more receiving communication devices 142 may then send a feedback message (eg, channel state information (CSI) feedback) to the transmitting communication device 102, which may receive the receiving communication device (s). The radio frequency block / module (s) 134 may be used to receive feedback messages. In another example, the transmitting communication device 102 may not receive an explicit feedback message from one or more receiving communication devices 142, but one or more receiver radio frequency blocks to estimate the channel. Other signals or messages received from one or more receiving communication devices 142 by module / module 134 may be used.

  [0080] The transmitting communication device 102 may include a multi-group communication block / module 114. Multi-group communication block / module 114 may be used to communicate with multiple groups of receiving communication devices 142. For example, the multi-group communication block / module 114 may use channel estimates based on signals provided by one or more receiver radio frequency blocks / modules 134. For example, channel estimates (eg, explicit feedback messages) may be provided to multi-group communication block / module 114 and / or multi-group communication block / module 114 received by receiver radio frequency block / module 134 The signal may be used to determine a channel estimate.

  [0081] The multi-group communication block / module 114 may determine the number of receiving communication devices 142. For example, the multi-group communication block / module 114 may determine the number of receiving communication devices 142 based on a signal received from the receiving communication device 142, such as a request to access communication resources provided by the transmitting communication device 102.

  [0082] The multi-group communication block / module 114 may divide the receiving communication device 142 into groups. For example, the multi-group communication block / module 114 may use the received signal to determine the grouping of the receiving communication device 142.

  [0083] In some configurations, the transmitting communication device 102 (eg, multi-group communication block / module 114) may use one approach or combination of techniques described below to determine the grouping. One approach is sometimes referred to as received signal strength ordering. Received signal strength ordering is one of the simplest approaches in which groups are formed based on similar signal strengths. In an actual multi-user channel, the signal strength can be closely related to the actual capacity of the downlink user. It may be advantageous to have all clients during downlink multi-user (MU) transmissions at approximately the same data rate. Another approach is sometimes referred to as single user data rate ordering. In practice, the transmitting communication device 102 may already have an estimate of the maximum achievable single user data rate. The transmitting communication device 102 may use the ordered rate to form a group, thereby generating, for example, one group with four highest rates and another group with four lowest rates. Yet another approach is sometimes referred to as capacity calculation. Based on explicit channel feedback (eg, compressed beamforming feedback in 802.11n or 802.11ac), the transmitting communication device 102 may calculate which two groups provide maximum capacity. However, this can be more difficult than the first two approaches described.

  [0084] In some configurations, the grouping may be based on the spatial location of the receiving communication device 142 in addition or alternatively. For example, the multi-group communication block / module 114 may divide eight receiving communication devices 142 into two groups of four, while the first group of four is in one spatial region, A second group consisting of is in another spatial region.

  [0085] The multi-group communication block / module 114 may include a precoding block / module 118. Precoding block / module 118 may be used to generate a precoding matrix that is used to beamform signals transmitted from one or more transmitter radio frequency blocks / modules 126. For example, the precoding matrix may include a weighting factor that weights transmissions from each of the antennas 132a-n. This may allow the transmitting communication device 102 to steer the transmitted signal in a particular spatial direction. The precoding matrix provided by multi-group communication block / module 114 may beamform the signal such that the signal or set of signals may be sent to a particular group of receiving communication devices 142. For example, a first signal or set of signals may be sent (using a first beam) to a first group of receiving communication devices 142, while a second signal or set of signals (second beam) To the second group of receiving communication devices 142.

  [0086] One or more receiving communication devices 142 may receive and use signals from the transmitting communication device 102. For example, the receiving communication device 142 uses the pilot sequence generated by the transmitting communication device 102 to characterize and characterize the channel, transmitter impairment and / or receiver impairment. May be used to improve reception of encoded data 104, 116 in transmission.

  [0087] For example, the receiving communication device 142 feeds one or more receiver radio frequency (RX RF) blocks 158 (rather than the number of transmitting communication device 102 antennas 132a-n and / or the number of spatial streams 138). One or more antennas 136a-n may be included (which may be more, less, or equal). One or more receiver radio frequency (RX RF) blocks 158 may output an analog signal to one or more analog to digital converters (ADC) 156. For example, the receiver radio frequency block 158 can receive and downconvert the signal, which can be provided to the analog to digital converter 156. As with the transmitting communication device 102, the number of spatial streams 138 processed may or may not be equal to the number of antennas 136a-n. Further, each spatial stream 138 need not be limited to one antenna 136, as various beam steering, orthogonalization, and other techniques can be used to arrive at multiple receiver streams.

  [0088] One or more analog-to-digital converters (ADC) 156 may convert the received analog signal (s) into one or more digital signals. These output (s) of one or more analog-to-digital converters (ADC) 156 may be provided to one or more time and / or frequency synchronization blocks / modules 154. The time and / or frequency synchronization block / module 154 may synchronize or align (e.g., attempt to synchronize or align) the digital signal in time and / or frequency (e.g., to the receiving communication device 142 clock).

  [0089] The (synchronized) output of the time and / or frequency synchronization (s) block / s (s) module 154 may be provided to one or more deformers 152. For example, the formatter 152 receives the output of the time and / or frequency synchronization (s) block / s module (s) 154, removes prefixes, etc., and / or discrete Fourier transforms ( Data can be parallelized for DFT) processing.

  [0090] One or more deformer 152 outputs may be provided to one or more discrete Fourier transform (DFT) blocks / modules 150. A discrete Fourier transform (DFT) block / module 150 may transform one or more signals from the time domain to the frequency domain. A pilot processor 148 may determine (eg, a spatial stream) to determine one or more pilot tones sent by the transmitting communication device 102 (eg, across a group of spatial streams 138, frequency subcarriers 140, and / or symbol periods). Frequency domain signals may be used (every 138). Pilot processor 148 may additionally or alternatively descramble the pilot sequence. Pilot processor 148 may use one or more pilot sequences for phase and / or frequency and / or amplitude tracking. The pilot tone (s) may be provided to a spatio-temporal frequency detection and / or decoding block / module 146 that detects and spans data across various dimensions. And / or can be decrypted. The spatio-temporal frequency detection and / or decoding block / module 146 may output received data 144 (eg, an estimate of the receiving communication device 142 of payload data 104 and / or overhead data 116 transmitted by the transmitting communication device 102).

  [0091] In accordance with the systems and methods disclosed herein, the spatio-temporal frequency detection / decoding block / module 146 provides spatial filtering, MIMO processing, and / or other interference cancellation techniques to obtain the data 144. Can be used. For example, when the transmitting communication device 102 divides the receiving communication device 142 into groups and transmits a signal or set of signals to each group, the receiving communication device 142 is responsible for all of the receiving communication devices 142 in that group. A signal may be received. Spatial filtering, MIMO processing, and / or other interference cancellation techniques may be used to convert data 144 intended for the receiving communication device 142 from data intended for one or more other receiving communication devices 142 in the group. Can be used to recover or separate.

  [0092] In some configurations, the receiving communication device 142 knows the transmission sequence sent as part of the entire information sequence. The receiving communication device 142 may perform channel estimation with the help of these known transmission sequences. To assist in pilot tone tracking, processing and / or data detection and decoding, channel estimation block / module 160 may use pilot processor 148 and / or time based on output from time and / or frequency synchronization block / module 154. An estimated signal may be provided to the spatial frequency detection and / or decoding block / module 146. Alternatively, if the deforming and discrete Fourier transform are the same as for the known transmission sequence with respect to the payload data portion of the total information sequence, the estimated signal is derived from the discrete Fourier transform (DFT) block / module 150. Based on the output, pilot processor 148 and / or spatio-temporal frequency detection and / or decoding block / module 146 may be provided.

  [0093] Additionally or alternatively, channel estimation block / module 160 may provide channel estimates to one or more transmitter radio frequency blocks / modules 162 for transmission to transmitting communication device 102. For example, channel estimation block / module 160 may use pilot and / or training symbols sent from transmitting communication device 102 to generate a channel feedback message. This channel feedback message may be provided to one or more transmitter radio frequency blocks / modules 162. One or more transmitter radio frequency blocks / modules 162 may transmit feedback messages to transmitting communication device 102 using one or more antennas 136a-n.

[0094] FIG. 2 is a block diagram illustrating an example of beamforming into multiple groups 266 of wireless communication devices 242 in accordance with the systems and methods disclosed herein. In this example, base station 202 transmits beamformed signals or beams 264a-n to multiple groups 266a-n of wireless communication devices 242a-n.
A base station 202 shown in FIG. 2 is an example of the transmission communication device 102. Base station 202 may use antennas 232a-n to transmit electromagnetic signals to wireless communication device 242. The wireless communication device 242 is an example of the receiving communication device 142. Each wireless communication device 242 may include one or more antennas 236 for receiving and / or transmitting electromagnetic signals. For example, the wireless communication device A 242a may include one or more antennas 236a-m, and the wireless communication device N242n may include one or more antennas 236n-z.

  [0095] Base station 202 includes a multi-group communication block / module 214. Multi-group communication block / module 214 may be used to communicate with multiple groups 266a-n of wireless communication devices 242a-n. For example, the multi-group communication block / module 214 may use channel estimates based on signals provided by the wireless communication device 242. For example, channel estimates (eg, explicit feedback messages) may be provided to multi-group communication block / module 214 and / or multi-group communication block / module 214 may use signals received from wireless communication device 242. A channel estimate may be determined.

  [0096] The multi-group communication block / module 214 may determine the number of wireless communication devices 242. For example, multi-group communication block / module 214 may determine the number of wireless communication devices 242 based on signals received from wireless communication devices 242, such as a request to access communication resources provided by base station 202.

  [0097] The multi-group communication block / module 214 may divide the wireless communication device 242 into groups 266a-n. For example, multi-group communication block / module 214 may use the received signal to determine a grouping of wireless communication devices 242. In some configurations, the grouping may be determined using one or more of the techniques described above with respect to FIG.

  [0098] The multi-group communication block / module 214 may include a precoding block / module 218. Precoding block / module 218 may be used to generate a precoding matrix that is used to beamform signals into beams 264a-n transmitted from base station 202. For example, the precoding matrix may include weighting factors that weight the transmissions from each of the antennas 232a-n. This may allow the base station 202 to steer the transmitted signal in a particular spatial direction. The precoding matrix provided by multi-group communication block / module 214 may beamform the signal such that the signal or set of signals may be sent in beam 264 to a particular group of wireless communication devices 242. For example, the first signal or set of signals may be sent (using the first beam 264a) to the first group 266a of the wireless communication device 242a, while the second signal or set of signals is (second To the second group 266n of wireless communication devices 242n.

  [0099] According to the systems and methods disclosed herein, each wireless communication device 242a-n can perform spatial filtering, MIMO processing, and / or other processing to obtain data transmitted from base station 202. Interference cancellation techniques may be used. For example, when the base station 202 divides the wireless communication device 242 into groups 266a-n and transmits a signal or set of signals to each group 266a-n, the wireless communication device 242 may be a wireless communication device in that group 266. Signals for all of 242 may be received. For example, all of the wireless communication devices 242 in group A 266a may receive a signal or set of signals sent using the first beam 264a. The signal or set of signals sent in the first beam 264a may include information about one, multiple, or all wireless communication devices 242 in group A 266a. Spatial filtering, MIMO processing and / or other interference cancellation techniques may be used to convert data intended for the wireless communication device 242 from data intended for one or more other wireless communication devices 242 in the group 266 thereof. Can be used to recover or separate.

  [00100] Thus, the systems and methods disclosed herein may enable MU-MIMO to multiple groups 266a-n. According to the systems and methods disclosed herein, for example, the number of downlink wireless communication devices (eg, clients) 242 may be divided into no more than four groups 266 in the case of resolvable LTFs, Or, in the case of an unsolvable LTF, it may be divided into 8 groups 266 or less. For example, base station (eg, access point) 202 may simultaneously beamform into multiple groups 266a-n such that the omnidirectional portion of the preamble is beamformed. In this way, each group 266a-n may “see” only the signaling related to that group 266a-n (eg, group A 266a may receive only the first beam 264a and group N 266n may receive the last Only beam 264n may be received). Further, wireless communication devices (eg, clients) 242 in one group 266 may receive reduced or minimal interference from transmissions to another group 266. Within one group 266, the base is set such that wireless communication devices (eg, clients) 242 in group 266 receive signals intended for all wireless communication devices (eg, clients) 242 in the same group 266. A station (eg, access point) 202 may use a resolvable LTF and some form of eigenmode selection (eg, minimum mean square error (MMSE) eigenmode selection (MMSE-ES) or multi-user eigenmode transmission (MET). ) And can be used.

  [00101] FIG. 3 is a flow diagram illustrating one configuration of a method 300 for multiple group communication. At 302, the transmitting communication device 102 determines the number of receiving communication devices 142. For example, the transmitting communication device 102 may determine the number of wireless communication devices 142 based on signals received from the wireless communication device 142, such as a request to access communication resources provided by the transmitting communication device 102. For example, one or more receiving communication devices 142 within the communication range of the transmitting communication device 102 attempt to establish a link with the transmitting communication device 102 or use resources provided by the transmitting communication device 102. A message may be sent to the sending communication device 102. The transmitting communication device 102 may take a tally of the identified receiving communication device 142 within the range that is attempting to communicate with the transmitting communication device 102. This record may be the number of receiving communication devices 142.

  [00102] At 304, the transmitting communication device 102 divides the number of receiving communication devices 142 into groups. For example, the transmitting communication device 102 may use the received signal to determine the grouping of the receiving communication device 142. For example, one or more of the techniques for determining the group described above with respect to FIG. 1 may be used.

  [00103] In some configurations, additional or alternative requirements may be taken into account. For example, the grouping may be based on the spatial location of the receiving communication device 142. For example, the transmitting communication device 102 is separate from the receiving communication device 142 to determine the spatial location (eg, direction) of the receiving communication device 142 or the direction of the signal received from the receiving communication device 142 relative to the transmitting communication device 102. The phase shifts or timing differences between the received signals may be used at the antennas 132a-n.

  [00104] Other additional or alternative requirements may be taken into account. For example, the receiving communication devices 142 may be grouped into groups with as large a number as possible. For example, the transmitting communication device 102 may divide the seven receiving communication devices 142 into groups of four and groups of four, where the group of four is the maximum group allowed. Other requirements may include distance. For example, the distance (between angles) can be used to determine the grouping. For example, assume that two receiving communication devices 142 are close to each other, but are separated from three other receiving communication devices 142 that are close to each other. In this case, the transmitting communication devices 102 may form a group of receiving communication devices 142 that are in close proximity to each other. Thus, the five receiving communication devices 142 can be grouped into groups of two and groups of three because two are away from three. Additional additional or alternative requirements may be taken into account, such as the capabilities of the receiving communication device 142, user preferences, resource usage, etc.

  [00105] At 306, the transmitting communication device 102 beamforms a signal based on the group. For example, the transmitting communication device 102 may generate a beam for each group of receiving communication devices 142, each beam carrying a signal or set of signals corresponding to each group. For example, the transmitting communication device 102 may generate a precoding matrix for each group of receiving communication devices 142. For example, the precoding matrix may include a weighting factor that weights the transmission for each antenna 132a-n of the transmitting communication device 102. This may allow the transmitting communication device 102 to steer the transmitted signal in a particular spatial direction. The group precoding matrix may beamform the signal such that the signal or set of signals may be sent to a particular group of receiving communication devices 142. For example, a first signal or set of signals may be sent (using a first beam) to a first group of receiving communication devices 142, while a second signal or set of signals (second beam) To the second group of receiving communication devices 142.

  [00106] At 308, the transmitting communication device 102 transmits a signal. For example, at 308, the transmitting communication device 102 may transmit a signal or set of signals to each group of receiving communication devices 142 using each of the group precoding matrix or steering matrix.

  [00107] FIG. 4 is a diagram illustrating an example of a communication frame 400 that can be used in accordance with the systems and methods disclosed herein. Frame 400 may include one or more sections or fields for preamble symbols, pilot symbols, and / or data symbols. For example, the frame 400 may comprise an IEEE 802.11ac preamble 468 and a data field 474 (eg, a data field or VHT-DATA field). In one configuration, the preamble 468 may have a duration of 40-68 microseconds (μs). Preamble 468 and / or pilot symbols may be used to synchronize, detect, demodulate, and / or decode preamble data (eg, overhead data 116) and / or payload data 104 included in frame 400 (eg, Used by the receiving communication device 142).

  [00108] A frame 400 with a preamble 468 that includes a number of fields may be structured. In one configuration, the 802.11ac frame 400 includes a legacy short training field or non-high throughput short training field (L-STF) 476, a legacy long training field or non-high throughput long training field (L-LTF) 478, and legacy Signal field or non-high throughput signal field (L-SIG) 480, very high throughput signal symbol or field A1 (VHT-SIG-A1) 482, and very high throughput signal symbol or field A2 (VHT-SIG-A2) 484 A very high throughput short training field (VHT-STF) 486 and one or more very high throughput long training fields (VHT-LTF) And 488, an ultra high-throughput signal field B (VHT-SIG-B) 490, may include a data field (DATA) 474.

  [00109] The preamble 468 may be adapted for transmit beamforming and MU-MIMO. A first part or portion 470 of preamble 468 may generally be transmitted in an omnidirectional manner (eg, using cyclic diversity or another manner). However, according to the systems and methods disclosed herein, this first or omnidirectional portion 470 can be beamformed. This first portion 470 of preamble 468 may include L-STF 476, L-LTF 478, L-SIG 480, VHT-SIG-A1 482, and VHT-SIG-A2 484. This first portion 470 of the preamble 468 may be decodable by legacy devices (eg, legacy or devices that conform to previous specifications).

  [00110] The second portion or portion 472 of the preamble 468 may be transmitted in an omni-directional manner, beamformed, or MU-MIMO precoded. This second portion 472 of preamble 468 includes VHT-STF 486, one or more VHT-LTF 488, and VHT-SIG-B 490. Data symbols (eg, in data field 474) may be transmitted with the same or different antenna pattern as second portion 472 of preamble 468. Data field 474 may also be transmitted omnidirectionally, beamformed, or MU-MIMO precoded. Data symbol and second portion 472 of preamble 468 may not be decodable by legacy devices (or even, for example, by all 802.11ac devices).

  [00111] The preamble 468 may include some control data that can be decoded by legacy 802.11a and 802.11n receivers. This control data is included in L-SIG480. Since all devices can suspend their transmission for a certain amount of time, the data in L-SIG 480 informs all receivers how long the transmission will occupy the wireless medium. In addition, preamble 468 allows an 802.11ac device to identify the transmission as an 802.11ac transmission (and avoid determining that the transmission is in 802.11a or 802.11n format). . Further, preamble 468 may cause legacy 802.11a and 802.11n devices to detect transmissions as 802.11a transmissions, which are valid transmissions with valid data in L-SIG 480.

  [00112] In one example, the preamble 468 can be used for 802.11a-based legacy concessions, as well as to carry 802.11ac information such as downlink MU-MIMO packets and bandwidth length. Or an omnidirectional portion 470. Preamble 468 may include any signaling specific to receiving communication device 142 (eg, client specific signaling), such as modulation and coding scheme (MCS) in the steered VHT-SIG-B490 symbol.

  [00113] The preamble 468 may have the possibility to use a resolvable long training field (LTF) or an unresolvable LTF. For resolvable LTFs, for example, the number of LTF symbols per receiving communication device (eg, client) 142 is equal to or greater than the total number of spatial streams 138 for all receiving communication devices (eg, clients) 142. large. For unresolvable LTFs, for example, the number of LTF symbols per receiving communication device (eg, client) 142 is equal to or greater than the number of spatial streams 138 per receiving communication device (eg, client) 142. .

  [00114] For resolvable LTFs, the number of receiving communication devices (eg, clients) 142 in a downlink MU-MIMO packet may be limited to four in the described preamble 468. For unresolvable LTFs, the number of receiving communication devices (eg, clients) 142 in a downlink MU-MIMO packet may be limited to eight in preamble 468. For this preamble 468, the total number of streams for all downlink receiving communication devices (eg, clients) 142 may not exceed eight.

  [00115] FIG. 5 is a diagram illustrating another example of a communication frame 500 that may be used in accordance with the systems and methods disclosed herein. Frame 500 may include one or more sections or fields for preamble symbols, pilot symbols, and / or data symbols. For example, frame 500 may comprise an IEEE 802.11ac preamble 568 and a data field 574 (eg, a data field or a VHT-DATA field). In one configuration, the preamble 568 may have a duration of 50-68 microseconds (μs). Preamble 568 and / or pilot symbols may be used to synchronize, detect, demodulate, and / or decode preamble data (eg, overhead data 116) and / or payload data 104 included in frame 500 (eg, Used by the receiving communication device 142).

  [00116] A frame 500 with a preamble 568 including several fields may be structured. In one configuration, the 802.11ac frame 500 includes a legacy short training field or non-high throughput short training field (L-STF) 576, a legacy long training field or non-high throughput long training field (L-LTF) 578, and a legacy Signal field or non-high throughput signal field (L-SIG) 580, very high throughput signal symbol or field A1 (VHT-SIG-A1) 582, and very high throughput signal symbol or field A2 (VHT-SIG-A2) 584 A very high throughput signal symbol or field A3 (VHT-SIG-A3) 592, and a very high throughput short training field (VHT-STF) 58. When, it may include one or more ultra-high-throughput long training field (VHT-LTF) 588, an ultra high-throughput signal field B (VHT-SIG-B) 590, and a data field (DATA) 574.

  [00117] The preamble 568 may be adapted for transmit beamforming and MU-MIMO. A first portion or portion 570 of preamble 568 may generally be transmitted in an omnidirectional manner (eg, using cyclic diversity or another manner). However, according to the systems and methods disclosed herein, this first or omnidirectional portion 570 can be beamformed. This first portion 570 of preamble 568 includes L-STF 576, L-LTF 578, L-SIG 580, VHT-SIG-A1 582, VHT-SIG-A2 584, and VHT-SIG-A3 592. May be included. This first portion 570 of the preamble 568 may be decodable by legacy devices (eg, legacy or devices that conform to previous specifications).

  [00118] The second portion or portion 572 of the preamble 568 may be transmitted in an omni-directional manner, beamformed, or MU-MIMO precoded. This second portion 572 of the preamble 568 includes a VHT-STF 586, one or more VHT-LTFs 588, and a VHT-SIG-B 590. Data symbols (eg, in data field 574) may be transmitted with the same or different antenna pattern as second portion 572 of preamble 568. Data field 574 can also be transmitted omnidirectionally, beamformed, or MU-MIMO precoded. Data symbol and second portion 572 of preamble 568 may not be decodable by legacy devices (or even, for example, by all 802.11ac devices).

  [00119] The preamble 568 may include some control data that can be decoded by legacy 802.11a and 802.11n receivers. This control data is included in L-SIG580. Since all devices can suspend their transmission for a certain amount of time, the data in L-SIG 580 informs all receivers how long the transmission will occupy the wireless medium. Further, preamble 568 allows an 802.11ac device to identify the transmission as an 802.11ac transmission (and avoid determining that the transmission is in 802.11a or 802.11n format). . In addition, preamble 568 may cause legacy 802.11a and 802.11n devices to detect transmissions as 802.11a transmissions, which are valid transmissions with valid data in L-SIG 580.

  [00120] In this example, the preamble 568 is used for 802.11a-based legacy concessions as well as to carry 802.11ac information such as downlink MU-MIMO packets and bandwidth length. Start with part 1 or omnidirectional part 570. More specifically, L-STF 576, L-LTF 578, L-SIG 580, VHT-SIG-A1 582, VHT-SIG-A2 584, and VHT-SIG-A3 592 may generally be transmitted in an omnidirectional manner. However, according to the systems and methods disclosed herein, the first or omnidirectional portion 570 can be beamformed. Preamble 568 may include all 802.11ac signaling information in omnidirectional portion 570, including downlink wireless communication device or per client modulation and coding scheme (MCS).

  [00121] The preamble 568 may have the possibility of using a resolvable long training field (LTF) or an unresolvable LTF. For resolvable LTFs, for example, the number of LTF symbols per wireless communication device (eg, client) 142 is equal to or greater than the total number of spatial streams 138 for all wireless communication devices (eg, clients) 142. large. For unresolvable LTFs, for example, the number of LTF symbols per wireless communication device (eg, client) 142 is equal to or greater than the number of spatial streams 138 per wireless communication device (eg, client) 142. .

  [00122] For resolvable LTFs, the number of wireless communication devices (eg, clients) 142 in a downlink MU-MIMO packet may be limited to four in the described preamble 568. For unresolvable LTFs, the number of wireless communication devices (eg, clients) 142 in downlink MU-MIMO packets may be limited to four in preamble 568. For this preamble 568, the total number of streams for all downlink wireless communication devices (eg, clients) 142 may not exceed eight.

  [00123] FIG. 6 is a flow diagram illustrating a more specific configuration of a method 600 for multiple group communication. At 602, base station 102 (eg, transmitting communication device 102) detects the number of wireless communication devices 142. For example, base station 102 may determine the number of wireless communication devices 142 based on signals received from wireless communication devices 142, such as a request to access communication resources provided by base station 102. For example, one or more wireless communication devices 142 within the communication range of base station 102 can establish a link with base station 102 or base a message attempting to use resources provided by base station 102. Can be sent to station 102. Base station 102 may keep track of identified wireless communication devices 142 within range that are attempting to communicate with base station 102. This record may be the number of wireless communication devices 142.

[00124] At 604, the base station 102 receives channel information. For example, at 604, the base station 102 receives channel information that can be used to determine a channel. An example of channel information is channel state information (CSI) according to the IEEE 802.11 specification. In one configuration, at 604, the base station 102 receives explicit channel feedback. For example, base station 102 may send training, sounding and / or pilot symbols to wireless communication device 142. The wireless communication device 142 may determine channel information (eg, CSI) based on training, sounding and / or pilot symbols and may send the channel information to the base station 102. In another configuration, at 604, the base station 102 receives implicit channel information.
For example, the wireless communication device 142 may send a signal that can be received and used by the base station 102 to determine the channel.

  [00125] At 606, the base station 102 divides the number of wireless communication devices 142 into groups based on the channel information. For example, base station 102 may use the received signal to determine the grouping of wireless communication devices 142. For example, the base station 102 may use one or more of the techniques for determining the groups described above with respect to FIG. One or more additional or alternative requirements may be taken into account, such as spatial location, signal direction, group size, distance between angles, wireless communication device 142 capabilities, user preferences, resource usage.

[00126] At 608, the base station 102 determines a precoding matrix for each group for beamforming. For example, base station 102 may generate a precoding matrix for each group of wireless communication devices 142 to generate a beam for each group, with each beam having a signal or set of signals corresponding to each group. Transport. For example, base station 102 may generate a precoding matrix for each group of wireless communication devices 142. The precoding matrix may include weighting factors that weight the transmission for each antenna 132a-n of the base station 102. This may allow the base station 102 to steer the transmitted signal in a particular spatial direction. The group precoding matrix may beamform the signal such that the signal or set of signals may be sent to a particular group of wireless communication devices 142.
For example, a first signal or set of signals may be sent (using a first beam) to a first group of wireless communication devices 142, while a second signal or set of signals (second beam) To the second group of wireless communication devices 142.

  [00127] In some configurations, at 608, determining a precoding matrix for each group may be performed to beamform the omnidirectional portion of the preamble. The omnidirectional portion of the preamble can be the portion of the preamble in a communication frame that is generally transmitted in an omnidirectional manner. For example, the omnidirectional portion 470 of the preamble 468 shown in FIG. 4 or the omnidirectional portion 570 of the preamble 568 shown in FIG. 5 is designated to be transmitted omnidirectionally (eg, by the IEEE specification). obtain. However, the omnidirectional portion 470 of the preamble 468 and the omnidirectional portion 570 of the preamble 568 can alternatively be beamformed to be transmitted in more than one beam according to the systems and methods disclosed herein. .

  [00128] At 610, the base station 102 transmits the beamformed signal to each group using the precoding matrix or steering matrix for each group. For example, at 610, the base station 102 transmits a signal or set of signals to each group of wireless communication devices 142 using each of the group precoding matrices. More specifically, the antenna weighting factors from the precoding matrix for each group may be applied to the electromagnetic signals that are then radiated from multiple base station 102 antennas 132a-n.

[00129] FIG. 7 is a flow diagram illustrating another more specific configuration of a method 700 for multiple group communications. For example, FIG. 7 illustrates using multi-group block diagonalization. At 702, the base station 102 determines a group channel for the current group. For example, base station 102 may receive a channel (shown as H) from one or more wireless communication devices 142 as explicit feedback. Alternatively, base station 102 may receive signals from one or more wireless communication devices 142 that base station 102 may use to determine channel H. Using channel H, at 702, base station 102 determines the current group channel H _k . The channel to group k may comprise H N _rxk rows and N _tx columns. N _rxk is the total number of receivers in group k and N _tx is the number of base station (eg, access point) transmitters.

[00130] At 704, the base station 102 uses the complement group channel

Judging. Complement group channel

May be a channel to all groups other than group k. That is,

_May comprise H N _rxt -N _rxk rows and N _tx columns, where N _rxt is the total number of wireless communication device (eg, client) receivers.

In [00131] 706, the base station 102 determines complement group channel null space V _n. For example, the base station 102 may calculate or calculate a singular value decomposition for the complement group channel, as shown in equation (3).

In equation (3), U ′ is

And S 'is

Singular value of V '

Of the right singular vector. Complement group channel null space V _n is the complement group channel

Or the last N _tx − (N _rxt −N _rxk ) sequence of V ′.

[00132] At 708, the base station 102 determines a client channel H _mk for each wireless communication device in the current group (eg, for m = 1 to N _ck ). For example, for m = 1 to N _ck , at 708, the base station 102 determines the channel H _mk to the wireless communication device (eg, client) m currently in the group (k). Client channel H _mk may comprise H N _rxmk rows and N _tx columns, where N _rxmk is the number of receivers of wireless communication device (eg, client) m in group k.

[00133] At 710, the base station 102 can determine the current group based on the client channel H _mk and the complement group channel null space V _n for each wireless communication device 142 (eg, for m = 1 to N _ck ). Determine the precoding matrix or steering matrix. This can be achieved in several ways. In the first example, the precoding matrix W _k for the current group may be determined according to Equation (4) and Equation (5).

In the formula (4), U _m includes left singular vectors of H _mk V _n, S _m is the singular value of H _mk V _n, V _m comprises a right singular vectors of H _mk V _n.

In equations (4) and (5), m is the index of the wireless communication device or client 142 and k is the group index. In one configuration, the precoding matrix W _k shown in equation (5) may be applied only to the first part or the omnidirectional part of the preamble. For example, the precoding matrix W _k shown in equation (5) includes preambles 468, 568 and VHT-SIG-A up to VHT-SIG-A, such as VHT-SIG-A2 484 or VHT-SIG-A3 592. Only applicable in preambles 468, 568.

[00134] In a second example of determining a precoding matrix at 710, the precoding matrix W _km for the current group may be determined according to Equation (6), Equation (7), and Equation (8). This second example may use minimum mean square error eigenmode selection within the group.

In the formula (6), U _m includes left singular vectors of H _mk V _n, S _m is the singular value of H _mk V _n, V _m comprises a right singular vectors of H _mk V _n.

In equation (7), m is the index of the wireless communication device or client, k is the group index, and N _ssmk is the number of spatial streams of the wireless communication device 142 (eg, client) m in group k. Z is a matrix with the selected eigenmode. Interference between these eigenmodes can be reduced or minimized by applying Equation (8).

In equation (8), the superscript ^H indicates conjugate transpose or Hermitian transpose, I is the identity matrix, and SNR _k is an estimate of the average signal-to-noise ratio (SNR) in the downlink for group k. .

[00135] In one configuration, the precoding matrix W _km for group k shown in equation (8) may be applied to the second portion of the preamble and / or the remaining portion of the packet or frame. Note that if precoding is performed for multiple groups, the precoding may need to be applied to the entire packet, including the entire preamble. For example, the precoding matrix W _km shown in Equation (8) may be applied to a frame 400 starting from VHT-STF 486 and a frame 500 starting from VHT-STF 586. Additionally or alternatively, the precoding matrix W _k shown in equation (5) is a first part of preambles 468, 568 up to VHT-SIG-A, such as VHT-SIG-A2 484 or VHT-SIG-A3 592. , And VHT-SIG-A can be applied only to the first part of the preambles 468, 568. Accordingly, determining the precoding matrix at 710 is determining the precoding matrix W _k as shown in equation (5) for the first portion of the preamble, and in one configuration, the remainder of the frame or packet. Can also include determining the precoding matrix W _km as shown in equation (8).

  [00136] The difference between the first example of precoding (eg, for the first part of the preamble) and the second example of precoding is the multi-user interference in the group in the first example. Note that no attempt is made to erase. For example, all the data in the same group for the first portion 470 of the preamble 468 (eg, up to VHT-STF 486), the first portion 570 of the preamble 568 (eg, up to VHT-STF 586), for example. This may not be necessary because it is the same for the wireless communication device (eg, client) 142.

[00137] However, in one configuration, the first portion 470 of the preamble 468 and the first portion 570 of the preamble 568 may be precoded equal to the second portion.
For example, the wireless communication device (eg, client) 142 cannot distinguish the spatial stream 138 before receiving the second portion and / or the remaining portion (eg, VHT-LTF, etc.) Interference between spatial streams can be canceled. If a wireless communication device (eg, client) 142 has more than one spatial stream 138, the first portion 470 of the preamble 468, the single stream 138 of the first portion 570 of the preamble 568 is the wireless communication device. (Eg, client) 142 may be copied to all stream inputs. The first portion 470 of the preamble 468 and the first portion 570 of the preamble 568 can be further decoded by all wireless communication devices (eg, clients) 142 because every spatial stream 138 contains the same information. This approach may actually be preferable because it requires only a single precoding matrix per packet instead of two different precoding matrices.

In [00138] 710 third example of determining the precoding matrix W _miles are as follows. This third example may use multi-group block diagonalization with multi-user eigenmode transmission (MET). As mentioned above, previous algorithms applied the least mean square error eigenmode selection within the group. One alternative is to use multi-user eigenmode transmission (MET) within the group. Note that the least mean square error eigenmode selection is simpler and may have better performance than this third example. Determining the precoding matrix according to this third example at 710 is shown in equation (9), equation (10), equation (11), equation (12), equation (13) and equation (14). Yes.

In the formula (9), U _m includes left singular vectors of H _mk V _n, S _m is the singular value of H _mk V _n, V _m comprises a right singular vectors of H _mk V _n.

In equation (10), m is the index of the wireless communication device or client 142, k is the group index, and N _ssmk is the number of spatial streams of the wireless communication device 142 (eg, client) m in group k. . D _m is the steering vector for wireless communication device 142 (eg, client) m.

In equation (11), Z is a matrix of steering vectors to all wireless communication devices 142 (eg, clients) in group k other than wireless communication device 142 (eg, client) m. Superscript ^H indicates conjugate transposition or Hermitian transposition.

In equation (12), U _mz includes the left singular vector of Z, S _mz is the singular value of Z, and V _mz includes the right singular vector of Z.

In equation (13), U is

Where S is the left singular vector

Is the singular value of V

Of the right singular vector. N _ssk is the number of spatial streams for group k.

In equation (14), W _km is a precoding matrix or steering matrix for wireless communication device 142 (eg, client) m in group k;

Is an identity matrix with N _ssmk rows and columns. Note that the term “precoding matrix” and the term “steering matrix” may be synonymous.

[00139] In a fourth example, flexible multi-group block diagonalization may be used in accordance with the systems and methods disclosed herein. In this example, for wireless communication device 142 (eg, client) c in group k, base station (eg, AP) 102 obtains only the beamforming matrix and the average signal-to-noise ratio (SNR) per stream, For example, the wireless communication device 142 (eg, client) c is

Through beamforming matrix

, But other (one or more) wireless communication devices (eg, clients) 142 have fed back channel state information H _mk . In this case, the base station (e.g., AP) 102 receives H _ck

(As well as the corresponding portion in H _k ), where H _ck is the channel for wireless communication device 142 (eg, client) c in group k and N _ssck is the wireless communication device in group k 142 (eg, client) c is the number of spatial streams 138. The rest of the processing has been described above, as described in the above example (eg, in equations (4)-(14), or in list (1), list (2) and / or list (3) above) It can be performed the same as a multi-group block diagonalization procedure. For example, assuming that the procedure shown in list (1) above is used, the wireless communication device 142 (eg, client) c is able to restore its data to recover its data as shown in equation (15). Dedicated spatial filtering may be applied at the receiving side.

In equation (15), U _c is given in list (1) for wireless communication device 142 (eg, client) m = c. Alternatively, depending on the MU-MIMO technique used, the receiver may perform any other type of MIMO processing or interference suppression (eg, assuming proper channel estimation is performed).

[00140] In a fifth example, flexible multi-group block diagonalization may be used in accordance with the systems and methods disclosed herein. In this example, for wireless communication device 142 (eg, client) c in group k, base station (eg, AP) 102 obtains only the beamforming matrix and singular values, eg, wireless communication device 142 (eg, client) C)

Through beamforming matrix

And singular values

However, it is assumed that other wireless communication devices (eg, clients) 142 have fed back channel state information H _mk . In this case, the base station (e.g., AP) 102 receives H _ck

(As well as the corresponding part in H _k ). The rest of the processing can be performed in the same way as the examples described previously (for example in equations (4) to (14), or in list (1), list (2) and / or list (3) above)). For example, assuming that the procedure shown in list (1) above is used, the wireless communication device 142 (eg, client) c is able to restore its data to recover its data as shown in equation (16). Dedicated spatial filtering may be applied at the receiving side.

In equation (16), U _c is given in list (1) for wireless communication device 142 (eg, client) m = c. Alternatively, depending on the MU-MIMO technique used, the receiver may perform any other type of MIMO processing or interference suppression (eg, assuming proper channel estimation is performed).

[00141] At 712, the base station 102 transmits a beamformed signal for the current group using a precoding matrix or a steering matrix.
For example, base station 102 may apply weights from a precoding matrix or steering matrix to signals transmitted from each of antennas 132a-n to antennas 132a-n.

[00142] Note that one or more of steps 702, 704, 706, 708, 710 and / or 712 shown in FIG. 7 may be repeated for each group in several groups _NG . For example, the base station 102 may repeat steps 702, 704, 706, 708 and 710 for k = 1 to _NG .

  [00143] FIG. 8 is a flow diagram illustrating another more specific configuration of a method 800 for multiple group communication. At 802, the base station 102 detects the number of wireless communication devices 142. For example, base station 102 may determine the number of wireless communication devices 142 based on signals received from wireless communication devices 142, such as a request to access communication resources provided by base station 102. For example, one or more wireless communication devices 142 within the communication range of base station 102 can establish a link with base station 102 or base a message attempting to use resources provided by base station 102. Can be sent to station 102. Base station 102 may keep track of identified wireless communication devices 142 within range that are attempting to communicate with base station 102. This record may be the number of wireless communication devices 142.

  [00144] At 804, the base station 102 sends a plurality of channel information (eg, channel state information or CSI) requests. In sending multiple channel information requests at 804, base station 102 may use at least one common antenna 132 for different channel information requests to the same wireless communication device 142.

[00145] In one configuration, channel state information (CSI) feedback may be used.
In 802.11ac, CSI feedback may be limited to 8 antennas. A base station (e.g., access point or AP) 102 with eight or more antennas 132a-n needs to send multiple feedback requests at 804 to get channels on all of its antennas 132a-n. possible.

  [00146] For up to 15 base stations (eg, APs) 102 transmit antennas 132a-n, an example procedure using channel state information is described as follows. At 804, the base station 102 sends a channel state information (CSI) request twice for each wireless communication device (eg, client) 142 and transmits from only eight antennas 132 each time (eg, what are all other antennas). Also don't send). Different channel state information (CSI) requests to the same wireless communication device (eg, client) 142 may need to include at least one common transmit antenna 132. This may be required to remove the phase shift that occurs between two different channel state information feedbacks. In one configuration, multiple channel state information messages (eg, CSI feedback) may be received (this is described below). Different (eg, multiple) channel state information feedback (eg, messages) by normalizing all channels by the value for that common antenna 132 such that the channel values for the common transmit antenna 132 are equal (match). ) Can be combined.

  [00147] For 15 or more antennas 132, the above procedure may be extended to 3 or more channel state information (CSI) requests, all with at least one common reference antenna 132. The above procedure may also be used in a group of four antennas 132 such that existing 802.11n channel state information feedback that may be limited to a maximum of four transmitters may be used.

  [00148] At 806, the base station 102 receives channel information. For example, at 806, the base station 102 receives channel information that can be used to determine a channel. In one configuration, the base station 102 may receive one or more (eg, multiple) channel state information messages from the same wireless communication device 142. An example of channel information is channel state information (CSI) according to the IEEE 802.11 specification. In one configuration, at 806, the base station 102 receives explicit channel feedback. For example, base station 102 may send training, sounding and / or pilot symbols to wireless communication device 142. The wireless communication device 142 may determine channel information (eg, CSI) based on training, sounding and / or pilot symbols and may send the channel information to the base station 102. In another configuration, at 806, the base station 102 receives implicit channel information. For example, the wireless communication device 142 may send a signal that can be received and used by the base station 102 to determine the channel.

  [00149] At 808, the base station 102 divides the number of wireless communication devices 142 into groups based on the channel information. For example, base station 102 may use the received signal to determine the grouping of wireless communication devices 142. In some configurations, the grouping may be determined using one or more of the techniques described above with respect to FIG.

  [00150] At 810, the base station 102 determines a precoding matrix or steering matrix for each group for beamforming. For example, base station 102 may generate a precoding matrix for each group of wireless communication devices 142 to generate a beam for each group, with each beam having a signal or set of signals corresponding to each group. Transport. For example, base station 102 may generate a precoding matrix for each group of wireless communication devices 142. The precoding matrix may include weighting factors that weight the transmission for each antenna 132a-n of the base station 102. This may allow the base station 102 to steer the transmitted signal in a particular spatial direction. The group precoding matrix may beamform the signal such that the signal or set of signals may be sent to a particular group of wireless communication devices 142. For example, a first signal or set of signals may be sent (using a first beam) to a first group of wireless communication devices 142, while a second signal or set of signals (second beam) To the second group of wireless communication devices 142.

  [00151] In some configurations, at 810, determining a precoding matrix for each group may be performed to beamform the omnidirectional portion of the preamble. The omnidirectional portion of the preamble can be the portion of the preamble in a communication frame that is generally transmitted in an omnidirectional manner. For example, the omnidirectional portion 470 of the preamble 468 shown in FIG. 4 or the omnidirectional portion 570 of the preamble 568 shown in FIG. 5 is designated to be transmitted omnidirectionally (eg, by the IEEE specification). obtain. However, the omnidirectional portion 470 of the preamble 468 and the omnidirectional portion 570 of the preamble 568 can alternatively be beamformed to be transmitted in more than one beam according to the systems and methods disclosed herein. .

  [00152] At 812, the base station 102 optionally uses media access control protection to prevent collisions. More particularly, media access control (MAC) protection may be used to prevent collisions from the wireless communication device (eg, station) 142. For example, a separate clear to send (CTS) signal may be sent before the downlink MU-MIMO packet. This CTS signal may notify wireless communication device 142 that a particular wireless communication device 142 may transmit a signal to base station 102. Other wireless communication devices 142 other than the wireless communication device designated to send may wait to transmit a signal until after a given period of time.

  [00153] At 814, the base station 102 transmits the beamformed signal to each group using the precoding matrix or steering matrix for each group. For example, at 814, the base station 102 transmits a signal or set of signals to each group of wireless communication devices 142 using each of the group precoding matrices. More specifically, the antenna weighting factors from the precoding matrix for each group may be applied to the electromagnetic signals that are then radiated from multiple base station 102 antennas 132a-n.

  [00154] FIG. 9 is a flow diagram illustrating one configuration of a method 900 for receiving group communications. At 902, the wireless communication device 142 optionally receives one or more channel information requests. For example, the wireless communication device 142 may receive one or more channel state information (CSI) requests from the base station 102. For example, the wireless communication device 142 may receive training symbols, pilot symbols, and / or sounding signals.

  [00155] At 904, the wireless communication device 142 optionally determines channel information. For example, the wireless communication device 142 may use received training symbols, pilot symbols, and / or sounding signals to determine channel (eg, feedback) information (eg, channel matrix).

  [00156] At 906, the wireless communication device 142 sends one or more signals. In one configuration, at 906, the wireless communication device 142 sends channel information (eg, feedback information) determined at 904 based on one or more signals received from the base station 102. Additionally or alternatively, the wireless communication device 142 may send a request to communicate with the base station 102. For example, the wireless communication device 142 may send a message to the base station 102 indicating that the wireless communication device 142 is communicating with the base station 102 resources and / or attempting to use the base station 102 resources. In some configurations, at 906, one or more signals sent to base station 102 may be used by base station 102 to determine channel information.

  [00157] At 908, the wireless communication device 142 receives a group signal. For example, at 908, the wireless communication device 142 receives a beamformed signal transmitted from the base station 102 that includes information about the group of wireless communication devices 142.

[00158] At 910, the wireless communication device 142 uses spatial filtering or another type of MIMO processing or interference suppression to recover data from the group signal. In one configuration, flexible multi-group block diagonalization may be used in accordance with the systems and methods disclosed herein. In this example, for wireless communication device 142 (eg, client) c in group k, base station (eg, AP) 102 obtains only the beamforming matrix and the average signal-to-noise ratio (SNR) per stream, For example, the wireless communication device 142 (eg, client) c is

Through beamforming matrix

, But other (one or more) wireless communication devices (eg, clients) 142 have fed back channel state information H _mk . In this case, the base station (e.g., AP) 102 receives H _ck

(As well as the corresponding portion in H _k ), where H _ck is the channel for wireless communication device (eg, client) c in group k, and N _ssck is the wireless communication device in group k ( For example, the number of spatial streams for client c). The rest of the processing has been described above, as described in the above example (eg, in equations (4)-(14), or in list (1), list (2) and / or list (3) above) It can be performed the same as a multi-group block diagonalization procedure. For example, assuming that the procedure shown in list (1) above is used, at 910, the wireless communication device 142 (eg, client) c receives the wireless communication device 142 as shown in equation (15) above. Dedicated spatial filtering is used at the receiving side of the wireless communication device 142 to recover the data.

[00159] In equation (15), U _c is given in list (1) for wireless communication device 142 (eg, client) m = c. Alternatively, depending on the MU-MIMO technique used, at 910, the wireless communication device 142 may perform any other type of MIMO processing or interference suppression (eg, assuming proper channel estimation is performed). use.

[00160] In another configuration, flexible multi-group block diagonalization may be used in accordance with the systems and methods disclosed herein. In this configuration, for wireless communication device 142 (eg, client) c in group k, base station (eg, AP) 102 obtains only the beamforming matrix and singular values, eg, wireless communication device 142 (eg, client) C)

Through beamforming matrix

And singular values

However, it is assumed that other wireless communication devices (eg, clients) 142 have fed back channel state information H _mk . In this case, the base station (e.g., AP) 102 receives H _ck

(As well as the corresponding part in H _k ). The rest of the processing can be performed in the same way as the examples described previously (eg in equations (4) to (14) or in list (1), list (2) and / or list (3) above) . For example, assuming that the procedure shown in list (1) above is used, at 910, wireless communication device 142 (eg, client) c may communicate with wireless communication device 142 as shown in equation (16) above. Use dedicated spatial filtering at its receiver to recover the data.

[00161] In equation (16), U _c is given in list (1) for wireless communication device 142 (eg, client) m = c. Alternatively, depending on the MU-MIMO technique used, at 910, the wireless communication device 142 may perform any other type of MIMO processing or interference suppression (eg, assuming proper channel estimation is performed). use.

  [00162] FIG. 10 is a block diagram illustrating one configuration of an access point 1002 and an access terminal 1042 in which systems and methods for multiple group communications may be implemented. The access point 1002 may be an example of the transmission communication device 102 illustrated in FIG. Access terminal 1042 may be an example of receiving communication device 142 shown in FIG.

  [00163] The access point 1002 may include overhead data 1016, payload data 1004, one or more transmitters 1026, one or more receivers 1034, and / or multi-group communication blocks / modules 1014. Payload data 1004 may include voice, video, audio and / or other data. Overhead data 1016 includes control information such as information specifying the data rate, modulation and coding scheme (MCS), channel bandwidth, frame length, concession period, collision protection information 1094 (eg, media access control (MAC) information, transmission Possible (CTS) information), and / or channel information requests (eg, channel state information (CSI) requests) 1092 and the like.

  [00164] One or more transmitters 1026 output radio frequency (RF) signals to one or more antennas 1032a-n, thereby suitable for reception by one or more access terminals 1042. Data 1004, 1016 may be transmitted over a wireless medium configured to Access point 1002 may also include one or more receivers 1034. One or more receivers 1034 may be used to receive signals from one or more access terminals 1042.

  [00165] Access point 1002 may detect the number of access terminals 1042. For example, the access point 1002 may determine the number of access terminals 1042 based on a signal received from the access terminal 1042, such as a request to access communication resources provided by the access point 1002, or feedback information. For example, one or more access terminals 1042 within the communication range of access point 1002 use one or more transmitters 1062 to establish a link with or provided by access point 1002. A message may be sent to the access point 1002 attempting to use the assigned resource. Access point 1002 may keep track of identified access terminals 1042 within range that are attempting to communicate with access point 1002. This record may be the number of access terminals 1042.

  [00166] In some configurations, the access point 1002 may send multiple channel information (eg, channel state information or CSI) requests 1092. In sending multiple channel information requests 1092, the access point 1002 may use at least one common antenna 1032 for different channel information requests to the same access terminal 1042.

  [00167] The access terminal 1042 may optionally receive one or more channel information requests 1092. For example, access terminal 1042 can receive one or more channel state information (CSI) requests 1092 from access point 1002. More specifically, access terminal 1042 may receive training symbols, pilot symbols, and / or sounding signals. In one configuration, the access point 1002 may transmit pilot and / or training symbols along with the channel information request 1092 to one or more access terminals 1042. One or more access terminals 1042 may receive pilot and / or training symbols using one or more receivers 1058.

  [00168] Access terminal 1042 may optionally determine channel information 1027. For example, access terminal 1042 can use received training symbols, pilot symbols, and / or sounding signals to determine channel (eg, feedback) information (eg, channel matrix) 1027. In one configuration, one or more receivers 1058 may provide received pilot and / or training symbols 1023 to channel estimation block / module 1025, which may provide them for channel estimation. Can be used. For example, channel estimation block / module 1025 may detect phase and / or frequency offsets in received pilot and / or training symbols that may be indicated in estimated channel 1027. The estimated channel 1027 may be provided to one or more transmitters 1062.

  [00169] The access terminal 1042 may send one or more signals. In one configuration, the access terminal 1042 may send the estimated channel 1027 as a feedback message (eg, channel state information (CSI) feedback) to the access point 1002, which may be one or more of the access points 1002. The receiver 1034 may be used to receive feedback messages. Additionally or alternatively, the access terminal 1042 can send a request to communicate with the access point 1002. For example, the access terminal 1042 may send a message to the access point 1002 indicating that the access terminal 1042 is communicating with the access point 1002 resource and / or attempting to use the access point 1002 resource. In some configurations, one or more signals sent to access point 1002 may be used by access point 1002 to determine channel information. For example, access point 1002 may not receive an explicit feedback message from one or more access terminals 1042, but one or more accesses by one or more receivers 1034 to estimate the channel. Other signals or messages received from terminal 1042 may be used. The estimated channel 1033 may be provided to the multi-group communication block / module 1014.

  [00170] Access point 1002 may divide the number of access terminals 1042 into groups based on channel information. For example, access point 1002 may use the received signal to determine access terminal 1042 grouping. In some configurations, the grouping may be determined using one or more of the techniques described above with respect to FIG.

[00171] Access point 1002 may determine a precoding matrix 1096 or steering matrix 1096 for each group for beamforming. For example, access point 1002 may generate a precoding matrix 1096 for each group of access terminals 1042 to generate a beam for each group, each beam having a signal or set of signals corresponding to each group. Transport. For example, access point 1002 can generate a precoding matrix 1096 for each group of access terminals 1042. Precoding matrix 1096 may include weighting factors that weight the transmission for each antenna 1032a-n of access point 1002.
This may allow the access point 1002 to steer the transmitted signal in a particular spatial direction. Group precoding matrix 1096 may beamform the signal such that the signal or set of signals may be sent to a particular group of access terminals 1042. For example, a first signal or set of signals may be sent (using a first beam) to a first group of access terminals 1042, while a second signal or set of signals (with a second beam). In use) may be sent to a second group of access terminals 1042.

  [00172] In some configurations, determining a precoding matrix for each group may be performed to beamform the omnidirectional portion of the preamble. The omnidirectional portion of the preamble can be the portion of the preamble in a communication frame that is generally transmitted in an omnidirectional manner. For example, the omnidirectional portion 470 of the preamble 468 shown in FIG. 4 or the omnidirectional portion 570 of the preamble 568 shown in FIG. 5 is designated to be transmitted omnidirectionally (eg, by the IEEE specification). obtain. However, the omnidirectional portion 470 of the preamble 468 and the omnidirectional portion 570 of the preamble 568 can alternatively be beamformed to be transmitted in more than one beam according to the systems and methods disclosed herein. .

  [00173] As described above, the access point 1002 includes a multi-group communication block / module 1014. In one configuration, the multi-group communication block / module 1014 includes a group channel decision block / module 1098, a client channel decision block / module 1003, a first singular value decomposition block / module 1009, a matrix multiplier 1035, a second singular value. Decomposition block / module 1015 and / or precoding matrix determination block / module 1021 may be included. In one configuration, the group channel determination block / module 1098 may determine the group channel 1001 for the current group. For example, group channel decision block / module 1098 may receive channel 1033 (shown as H) from one or more access terminals 1042 as explicit feedback. Alternatively, access point 1002 may receive a signal from one or more access terminals 1042 that access point 1002 may use to determine channel H 1033.

[00174] Using the channel H1033, group channel decision block / module 1098 may determine current group channel H _k 1001. The channel 1001 to group k may comprise H N _rxk rows and N _tx columns. Group channel decision block / module 1098 is a complementary group channel

1005 can be determined. Complement group channel

1005 may be a channel to all groups other than group k.

[00175] The first singular value decomposition block / module 1009 may determine the complement group channel null space V _n 1011. For example, the first singular value decomposition block / module 1009 may calculate or calculate the singular value decomposition for the complement group channel, as shown in equation (3) above. Complement group channel null space V _n 1011 is the complement group channel

1005 null space.

[00176] Client channel determination block / module 1003 may determine a client channel H _mk 1007 for each access terminal in the current group (eg, for m = 1 to N _ck ). For example, for m = 1 to N _ck , the client channel determination block / module 1003 may determine the channel H _mk 1007 to the access terminal (eg, client) m currently in the group (k). Client channel H _mk 1007 may comprise H N _rxmk rows and N _tx columns, where N _rxmk is the number of receivers 1058 for access terminal 1042 (eg, client) m in group k.

[00177] The multi-group communication block / module 1014 is based on the client channel H _mk 1007 and the complement group channel null space V _n 1011 for each access terminal 1042 (eg, for m = 1 to N _ck ) A precoding matrix 1096 or steering matrix 1096 for the group may be determined. This can be achieved in several ways. In the configuration illustrated in FIG. 10, the matrix multiplier 1035 may multiply the client channel H _mk 1007 and the complement group channel null space V _n 1011. The product H _mk V _n 1013 may be provided to a second singular value decomposition block / module 1015.

[00178] The second SVD block / module 1015, S _m 1019 (for example, singular value of H _mk V _n 1013), (e.g., including the right singular vectors of _{H mk V n 1013) V m} 1017 And can be generated. This can be done, for example, as shown in equation (4), equation (6) or equation (9) above.

[00179] S _m 1019 and V _m 1017 may be provided to a precoding matrix decision block / module 1021. In one configuration, the precoding matrix determination block / module 1021 may determine a precoding matrix or steering matrix 1096 as shown in equation (5) above. In another configuration, the precoding matrix determination block / module 1021 may determine the precoding matrix or steering matrix 1096 as shown in equation (7) or equation (8) above. In some configurations, the precoding matrix determination block / module 1021 determines a precoding matrix or steering matrix 1096 as shown in equation (5) for a first portion of a preamble (eg, an omnidirectional portion). The precoding matrix or steering matrix 1096 may be determined as shown in equations (7) and (8) for the second portion of the preamble and / or for the remainder of the frame. In other configurations, the precoding matrix determination block / module 1021 determines the precoding matrix or steering matrix 1096 as shown in equations (7) and (8) for the entire preamble and / or for the entire frame. obtain.

  [00180] In yet another configuration, the precoding matrix decision block / module 1021 is as shown in Equation (10), Equation (11), Equation (12), Equation (13), and Equation (14) above. A precoding matrix or steering matrix 1096 may be determined. For example, the precoding matrix determination block / module 1021 may determine a matrix of steering vectors, perform further singular value decomposition, and the like.

  [00181] The access point may use a precoding matrix or steering matrix 1096 to beamform payload data 1004 and / or overhead data 1016. For example, a precoding matrix or steering matrix 1096 may be provided to one or more transmitters 1026 and thus may weight the transmission on each antenna 1032a-n. The (weighted) transmission signal may be received by one or more access terminals 1042. For example, data 1004, 1016 for a group of access terminals 1042 may be conveyed to the group of access terminals 1042 in a beamformed signal. Each of the access terminals 1042 may receive (weighted) transmission signals using their respective antenna (s) 1036 and receiver (s) 1058. Received signal 1099 may be provided to spatial filtering / MIMO processing / interference suppression block / module 1029. Spatial filtering / MIMO processing / interference suppression block / module 1029 may perform spatial filtering, MIMO processing, and / or some other type of interference suppression to recover data 1031 for access terminal 1042.

[00182] The access point 1002 may additionally or alternatively use flexible multi-group block diagonalization as described above. For example, for access terminal 1042 (eg, client) c in group k, access point 1002 obtains only the beamforming matrix and average signal to noise ratio (SNR) per stream, eg, access terminal 1042 (eg, Client) c

Through beamforming matrix

Assume that other access terminals (eg, clients) 1042 have fed back channel state information H _mk . In this case, the multi-group communication block / module 1014 receives H _ck as described above.

(As well as the corresponding part in H _k 1001). The rest of the processing can be performed in the same way as the multi-group block diagonalization procedure described above. For example, assuming that the procedure shown in list (1) above is used, access terminal 1042 (eg, client) c may restore its data 1031 as shown in equation (15) above. In addition, dedicated spatial filtering may be applied by the spatial filtering block / module 1029. Alternatively, depending on the MU-MIMO technique used, the spatial filtering / MIMO processing / interference suppression block / module 1029 may be used to recover the data 1031 (eg, assuming appropriate channel estimation is performed). ) Any other type of MIMO processing or interference suppression may be performed.

[00183] Additionally or alternatively, the access point 1002 may use another type of flexible multi-group block diagonalization. For example, for access terminal 1042 (eg, client) c in group k, access point 1002 obtains only the beamforming matrix and singular values, for example, access terminal 1042 (eg, client) c

Through beamforming matrix

And singular values

However, it is assumed that other access terminals (eg, clients) 1042 have fed back channel state information H _mk . In this case, the access point 1002 receives H _ck

(As well as the corresponding part in H _k ). The rest of the processing can be performed as described above. For example, assuming that the procedure shown in list (1) above is used, access terminal 1042 (eg, client) c may restore its data 1031 as shown in equation (16) above. In addition, dedicated spatial filtering may be applied by the spatial filtering block / module 1029. Alternatively, depending on the MU-MIMO technique used, the spatial filtering block / module 1029 may use any other type to recover the data 1031 (eg, assuming proper channel estimation is performed). MIMO processing or interference suppression may be performed.

[00184] Note that a precoding matrix 1096 or steering matrix 1096 may be generated for each group of access terminals 1042 in several groups _NG . Additionally or alternatively, group precoding matrix 1096 or steering matrix 1096 may be used individually and / or combined into a single precoding matrix or steering matrix.

  [00185] The access point 1002 may optionally use collision protection information 1094 (eg, media access control protection) to prevent collisions. More particularly, media access control (MAC) protection may be used to prevent collisions from access terminals (eg, stations) 1042. For example, a separate transmit ready (CTS) signal may be sent before the downlink MU-MIMO packet. This CTS signal may notify access terminal 1042 that a particular access terminal 1042 may transmit a signal to access point 1002. Other access terminals 1042 other than the access terminal designated to send may wait to send a signal until after a given period of time.

  [00186] Access point 1002 may transmit the beamformed signal to each group of access terminals 1042 using precoding matrix 1096 or steering matrix 1096 for each group. For example, access point 1002 may transmit a signal or set of signals to each group of access terminals 1042 using each of group precoding matrix 1096. More specifically, the antenna weighting factors from the precoding matrix for each group may be applied to the electromagnetic signals that are then radiated from multiple access point 1002 antennas 1032a-n.

  [00187] Access terminal 1042 may receive a group signal. For example, access terminal 1042 may receive a beamformed signal transmitted from access point 1002 that includes information about the group of access terminals 1042. This may be done using its one or more antennas 1036a-n and one or more receivers 1058. As explained above, access terminal 1042 may use spatial filtering or another type of MIMO processing or interference suppression to recover data from the group signal. For example, the spatial filtering / MIMO processing / interference suppression block / module 1029 may perform spatial filtering, MIMO processing and / or on one or more received signals 1099 to recover data 1031 for the access terminal 1042. Any other type of interference suppression may be performed.

  [00188] FIG. 11 is a block diagram of a base station 1102 that may be used in a multiple-input multiple-output (MIMO) system. Examples of base station 1102 may include transmitting communication device 102, base station 202, and access point 802 shown above. Base station 1102 may be configured similarly to transmitting communication device 102, base station 202, and / or access point 802 shown above, or vice versa. At base station 1102, traffic data for several data streams is provided from one or more data sources 1137 and / or application processors 1139 to a baseband processor 1143. In particular, traffic data may be provided to a transmission processing block / module 1147 included in the baseband processor 1143. Each data stream may then be transmitted via a respective transmit antenna 1159a-n. Transmission processing block / module 1147 may format, code, and interleave traffic data for each data stream based on the particular coding scheme selected for that data stream to provide coded data.

[00189] The coded data for each data stream may be multiplexed with pilot data from pilot generator 1145 using orthogonal frequency division multiplexing (OFDM) techniques.
The pilot data may be a known data pattern that is processed in a known manner and used at the receiver to estimate the channel response. The multiplexed pilot and coded data for each stream is then sent to a specific modulation scheme (eg, 2 phase shift keying (BPSK), 4 phase shift keying) selected for that data stream to provide modulation symbols. (QPSK), multiple phase shift keying (M-PSK), quadrature amplitude modulation (QAM) or multi-level quadrature amplitude modulation (M-QAM)). The data rate, coding, and modulation for each data stream may be determined by instructions executed by the processor.

  [00190] Modulation symbols for all data streams may be provided to a transmit (TX) multiple-input multiple-output (MIMO) processing block / module 1155, and transmit (TX) multiple-input multiple-output (MIMO) processing block / module 1155. May further process modulation symbols (eg, for OFDM). A transmit (TX) multiple-input multiple-output (MIMO) processing block / module 1155 then provides several modulation symbol streams to the transmitters 1157a-n. TX transmit (TX) multiple-input multiple-output (MIMO) processing block / module 1155 may further apply beamforming weights to the symbols of the data stream and to the antenna 1159 from which the symbols are transmitted.

  [00191] Each transmitter 1157 receives and processes a respective symbol stream to provide one or more analog signals and further condition (eg, amplify, filter, and up) those analog signals. Converted) to provide a modulated signal suitable for transmission over a MIMO channel. The modulated signals from transmitters 1157a-n are then transmitted from antennas 1159a-n, respectively. For example, the modulated signal can be transmitted to another communication device (not shown in FIG. 11).

  [00192] Base station 1102 may receive a modulated signal (from another communication device). These modulated signals are received by antenna 1159 and adjusted (eg, filtered, amplified, downconverted, digitized) by receiver 1157. In other words, each receiver 1157 adjusts (eg, filters, amplifies, and downconverts) its respective received signal, digitizes the adjusted signal, provides samples, and further processes those samples. May provide a corresponding “received” symbol stream.

[00193] A receive processing block / module 1151 included in the baseband processor 1143 then receives the symbol stream received from the receiver 1157 and processes based on a particular receiver processing technique to produce a number of " Gives the "detected" stream.
The receive processing block / module 1151 demodulates, deinterleaves, and decodes each stream to recover the traffic data of the data stream.

  [00194] Precoding processing block / module 1161 included in baseband processor 1143 may receive channel state information (CSI) from receiving processing block / module 1151. The precoding processing block / module 1161 then determines which precoding matrix to use to determine the beamforming weights and then processes the extracted message. Note that the baseband processor 1143 can store information on the baseband memory 1153 and retrieve information from the baseband memory 1153.

  [00195] The precoding processing block / module 1161 may perform one or more of the methods 300, 600, 700, 800 shown above. For example, the precoding processing block / module 1161 may include a multi-group communication block / module 1149. Multi-group communication block / module 1149 may provide instructions to allow base station 1102 to communicate with multiple groups of communication devices (eg, receiving communication device 142, wireless communication device 242, access terminal 1042, etc.). Can be executed.

  [00196] The traffic data restored by the baseband processor 1143 may be provided to the application processor 1139. Application processor 1139 may store information in application memory 1141 and retrieve information from application memory 1141.

  [00197] FIG. 12 illustrates several components that may be included within a transmitting communication device, base station, and / or access point 1202. The transmitting communication device 102, base stations 202, 1102 and / or access point 1002 described above may be configured similarly to the transmitting communication device / base station / access point 1202 shown in FIG.

[00198] The transmitting communication device / base station / access point 1202 includes a processor 1279. The processor 1279 may be a general purpose single or multi-chip microprocessor (eg, ARM), a dedicated microprocessor (eg, digital signal processor (DSP)), a microcontroller, a programmable gate array, and the like.
The processor 1279 may be referred to as a central processing unit (CPU). Although only a single processor 1279 is shown in the transmitting communication device / base station / access point 1202 of FIG. 12, in an alternative configuration, a combination of processors (eg, an ARM and DSP) may be used.

  [00199] The transmitting communication device / base station / access point 1202 also includes a memory 1263 in electronic communication with the processor 1279 (ie, the processor 1279 reads information from the memory 1263 and / or stores information in the memory 1263). Can write). Memory 1263 may be any electronic component capable of storing electronic information. Memory 1263 includes random access memory (RAM), read only memory (ROM), magnetic disk storage media, optical storage media, flash memory devices in RAM, on-board memory included with the processor, programmable read only memory (PROM), It may be an erasable programmable read only memory (EPROM), an electrically erasable PROM (EEPROM®), a register, etc., and combinations thereof.

  [00200] Data 1265 and instructions 1267 may be stored in memory 1263. Instruction 1267 may include one or more programs, routines, subroutines, functions, procedures, code, and the like. Instruction 1267 may include a single computer readable statement or a number of computer readable statements. Instruction 1267 may be executable by processor 1279 to implement the methods 300, 600, 700, 800 described above. Executing instructions 1267 may include the use of data 1265 stored in memory 1263. FIG. 12 shows some instructions 1267a and data 1265a being loaded into the processor 1279.

  [00201] The transmitting communication device / base station / access point 1202 is also a signal between the transmitting communication device / base station / access point 1202 and a remote location (eg, another transmitting communication device, access terminal, access point, etc.). A transmitter 1275 and a receiver 1277 may be included to enable transmission and reception of. Transmitter 1275 and receiver 1277 may be collectively referred to as transceiver 1273. Antenna 1271 can be electrically coupled to transceiver 1273. The transmitting communication device / base station / access point 1202 may also include multiple transmitters, multiple receivers, multiple transceivers, and / or multiple antennas (not shown).

  [00202] The various components of the transmitting communication device / base station / access point 1202 may be coupled to each other by one or more buses, which may include a power bus, a control signal bus, a status signal bus, a data bus, and the like. For simplicity, the various buses are shown as bus system 1269 in FIG.

  [00203] FIG. 13 illustrates several components that may be included within the receiving communication device, the wireless communication device, and / or the access terminal 1342. One or more of the receiving communication device 142, wireless communication device 242 and / or access terminal 1042 described above may be configured similarly to the receiving communication device / wireless communication device / access terminal 1342 shown in FIG.

[00204] The receiving communication device / wireless communication device / access terminal 1342 includes a processor 1399. The processor 1399 may be a general purpose single or multi-chip microprocessor (eg, ARM), a dedicated microprocessor (eg, digital signal processor (DSP)), a microcontroller, a programmable gate array, and the like. The processor 1399 may be referred to as a central processing unit (CPU).
Although only a single processor 1399 is shown in the receiving communication device / wireless communication device / access terminal 1342 of FIG. 13, in an alternative configuration, a combination of processors 1399 (eg, an ARM and DSP) may be used.

  [00205] Receiving communication device / wireless communication device / access terminal 1342 also includes memory 1381 in electronic communication with processor 1399 (ie, processor 1399 reads information from and / or stores information in memory 1381). Can be written). Memory 1381 can be any electronic component capable of storing electronic information. Memory 1381 includes random access memory (RAM), read only memory (ROM), magnetic disk storage media, optical storage media, flash memory device in RAM, on-board memory included with processor 1399, programmable read only memory (PROM) Erasable programmable read only memory (EPROM), electrically erasable PROM (EEPROM), registers, etc., and combinations thereof.

[00206] Data 1383a and instructions 1385a may be stored in the memory 1381.
Instruction 1385a may include one or more programs, routines, subroutines, functions, procedures, code, and the like. Instruction 1385a may include a single computer readable statement or a number of computer readable statements. Instruction 1385a may be executable by processor 1399 to implement method 900 disclosed herein. Executing instruction 1385a may involve the use of data 1383a stored in memory 1381. FIG. 13 shows some instructions 1385b and data 1383b (which may come from instructions 1385a and data 1383a in memory 1381) loaded into processor 1399.

  [00207] The receiving communication device / wireless communication device / access terminal 1342 also transmits and receives signals between the receiving communication device / wireless communication device / access terminal 1342 and a remote location (eg, communication device, base station, etc.). To enable a transmitter 1395 and a receiver 1397 may be included. Transmitter 1395 and receiver 1397 may be collectively referred to as transceiver 1393. Antenna 1391 may be electrically coupled to transceiver 1393. Receiving communication device / wireless communication device / access terminal 1342 may also include multiple transmitters 1395, multiple receivers 1397, multiple transceivers 1393, and / or multiple antennas 1391 (not shown).

[00208] The receiving communication device / wireless communication device / access terminal 1342 may include one or more microphones for capturing acoustic signals. In one configuration, the microphone may be a transducer that converts an acoustic signal (eg, voice, speech) into an electrical or electronic signal. Additionally or alternatively, the receiving communication device / wireless communication device / access terminal 1342 may include one or more speakers.
In one configuration, the speaker may be a transducer that converts an electrical or electronic signal into an acoustic signal.

  [00209] The various components of the receiving communication device / wireless communication device / access terminal 1342 may be coupled together by one or more buses, which may include a power bus, a control signal bus, a status signal bus, a data bus, etc. . For simplicity, the various buses are shown as bus system 1301 in FIG.

  [00210] In the above description, reference numbers have sometimes been used along with various terms. Where a term is used with a reference number, this may refer to a particular element shown in one or more of the figures. Where a term is used without a reference number, this may generally refer to a term not limited to a particular figure.

  [00211] The term “determining” encompasses a wide variety of actions, and thus “determining” is a calculation, calculation, processing, derivation, investigation, lookup (eg, table, database or other data). (Lookup in structure), confirmation, etc. Also, “determining” can include receiving (eg, receiving information), accessing (eg, accessing data in a memory), and the like. Also, “determining” can include solution, selection, selection, establishment, and the like.

  [00212] The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” represents both “based only on” and “based at least on”.

  [00213] The functionality described herein may be stored as one or more instructions on a processor-readable medium or computer-readable medium. The term “computer-readable medium” refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such media may be in the form of RAM, ROM, EEPROM, flash memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage device, or instructions or data structures Any other medium that can be used to store the program code and that can be accessed by a computer or processor. Discs and discs used herein are compact discs (CDs), laser discs (discs), optical discs (discs), digital versatile discs (discs) DVD, floppy disk, and Blu-ray disk, which typically reproduces data magnetically, and the disk lasers the data To reproduce optically. Note that computer-readable media can be tangible and non-transitory. The term “computer-program product” refers to a computing device or processor in combination with code or instructions (eg, a “program”) that can be executed, processed or calculated by the computing device or processor. The term “code” as used herein may refer to software, instructions, code or data that is executable by a computing device or processor.

  [00214] Software or instructions may also be transmitted over a transmission medium. For example, the software can use a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared, wireless, and microwave, from a website, server, or other remote source When transmitted, coaxial technologies, fiber optic cables, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of transmission media.

  [00215] The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and / or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the methods described herein, the order and / or use of specific steps and / or actions is within the scope of the claims. Modifications can be made without departing.

に従って達成され、

が前記コンプリメントグループチャネルであり、Ｕ’が

の左特異ベクトルを含み、Ｓ’が

の特異値であり、Ｖ’が

の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、前記コンプリメントグループチャネル零空間Ｖ _n がＶ’の最後のＮ _tx −（Ｎ _rxt −Ｎ _rxk ）列を備える、ここで、Ｎ _tx が基地局送信機の数であり、Ｎ _rxt がワイヤレス通信デバイス受信機の総数であり、Ｎ _rxk がグループｋの受信機の総数である、Ｃ４に記載の基地局。
［Ｃ６］
前記現在グループについての前記プリコーディング行列を判断することが、式［Ｕ _m ，Ｓ _m ，Ｖ _m ］＝ｓｖｄ（Ｈ _mk Ｖ _n ）と式

とに従って達成される、ここで、Ｈ _mk が前記クライアントチャネルであり、Ｖ _n が前記コンプリメントグループチャネル零空間であり、Ｕ _m がＨ _mk Ｖ _n の左特異ベクトルを含み、Ｓ _m がＨ _mk Ｖ _n の特異値であり、Ｖ _m がＨ _mk Ｖ _n の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、Ｗ _k がグループｋについての前記プリコーディング行列であり、ｍが指数である、Ｃ４に記載の基地局。
［Ｃ７］
前記現在グループについての前記プリコーディング行列を判断することが、式［Ｕ _m ，Ｓ _m ，Ｖ _m ］＝ｓｖｄ（Ｈ _mk Ｖ _n ）と、式Ｚ（：，（ｍ−１）Ｎ _ssmk ＋１：ｍ＊Ｎ _ssmk ）＝Ｖ _m （：，１：Ｎ _ssmk ）Ｓ _m （１：Ｎ _ssmk ，１：Ｎ _ssmk ）と式

とに従って達成される、ここで、Ｈ _mk が前記クライアントチャネルであり、Ｖ _n が前記コンプリメントグループチャネル零空間であり、Ｕ _m がＨ _mk Ｖ _n の左特異ベクトルを含み、Ｓ _m がＨ _mk Ｖ _n の特異値であり、Ｖ _m がＨ _mk Ｖ _n の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、Ｎ _ssmk がグループｋ中のワイヤレス通信デバイスｍの空間ストリームの数であり、Ｚが、選択された固有モードを備える行列であり、上付き文字 ^H が共役転置を示し、Ｉが単位行列であり、ＳＮＲ _k が前記グループｋについてのダウンリンクにおける平均信号対雑音比（ＳＮＲ）の推定値であり、Ｗ _km が前記プリコーディング行列である、Ｃ４に記載の基地局。
［Ｃ８］
前記現在グループについての前記プリコーディング行列を判断することが、式［Ｕ _m ，Ｓ _m ，Ｖ _m ］＝ｓｖｄ（Ｈ _mk Ｖ _n ）と、式Ｄ _m ＝Ｖ _m （：，１：Ｎ _ssmk ）Ｓ _m （１：Ｎ _ssmk ，１：Ｎ _ssmk ）と、式

と、式

と、式

とに従って達成される、ここで、Ｈ _mk が前記クライアントチャネルであり、Ｖ _n が前記コンプリメントグループチャネル零空間であり、Ｕ _m がＨ _mk Ｖ _n の左特異ベクトルを含み、Ｓ _m がＨ _mk Ｖ _n の特異値であり、Ｖ _m がＨ _mk Ｖ _n の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、Ｎ _ssmk がグループｋ中のワイヤレス通信デバイスｍの空間ストリームの数であり、Ｄ _m が前記ワイヤレス通信デバイスｍについてのステアリングベクトルであり、Ｚが、前記ワイヤレス通信デバイスｍ以外の前記グループｋ中のすべてのワイヤレス通信デバイスのステアリングベクトルの行列であり、上付き文字 ^H が共役転置を示し、Ｎ _ck が前記グループｋ中のワイヤレス通信デバイスの数であり、Ｕ _mz がＺの左特異ベクトルを含み、Ｓ _mz がＺの特異値であり、Ｖ _mz がＺの右特異ベクトルを含み、Ｕが

の左特異ベクトルを含み、Ｓが

の特異値であり、Ｖが

の右特異ベクトルを含み、Ｎ _ssk が前記グループｋについての空間ストリームの数であり、

がＮ _ssmk 個の行および列をもつ単位行列であり、ＳＮＲ _k が前記グループｋについてのダウンリンクにおける平均信号対雑音比（ＳＮＲ）の推定値であり、Ｗ _km が前記プリコーディング行列である、Ｃ４に記載の基地局。
［Ｃ９］
現在グループについての前記プリコーディング行列がプリアンブルの第１の部分に適用され、前記命令が、前記プリアンブルの第２の部分に適用される前記現在グループについての第２のプリコーディング行列を判断するようにさらに実行可能である、Ｃ１に記載の基地局。
［Ｃ１０］
前記命令が、
異なるチャネル状態情報要求のために少なくとも１つの共通アンテナを使用して、複数のチャネル状態情報要求を同じワイヤレス通信デバイスに送ることと、
前記同じワイヤレス通信デバイスから複数のチャネル状態情報メッセージを受信することと、
前記複数のチャネル状態情報メッセージを組み合わせることと
を行うようにさらに実行可能である、Ｃ１に記載の基地局。
［Ｃ１１］
前記命令が、メディアアクセス制御保護を使用するようにさらに実行可能である、Ｃ１に記載の基地局。
［Ｃ１２］
前記現在グループについての前記プリコーディング行列を判断することが、Ｈ _ck を

に設定することによって達成される、ここで、Ｈ _ck がグループｋ中のワイヤレス通信デバイスｃについてのチャネルであり、

が前記ワイヤレス通信デバイスｃについてのビームフォーミング行列であり、Ｎ _ssck が前記グループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、上付き文字 ^H が共役転置を示す、Ｃ４に記載の基地局。
［Ｃ１３］
前記現在グループについての前記プリコーディング行列を判断することが、Ｈ _ck を

に設定することによって達成される、ここで、Ｈ _ck がグループｋ中のワイヤレス通信デバイスｃについてのチャネルであり、

が前記ワイヤレス通信デバイスｃについてのビームフォーミング行列であり、

が前記ワイヤレス通信デバイスｃについての特異値であり、Ｎ _ssck が前記グループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、上付き文字 ^H が共役転置を示す、Ｃ４に記載の基地局。
［Ｃ１４］
プロセッサと、
前記プロセッサと電子通信しているメモリと、
前記メモリに記憶された命令と
を備える、グループ信号を受信するためのワイヤレス通信デバイスであって、前記命令が、
２つ以上のワイヤレス通信デバイスについての情報を含むグループ信号を受信することと、
空間フィルタ処理を使用して、前記グループ信号から前記ワイヤレス通信デバイスについてのデータを復元することと
を行うように実行可能である、ワイヤレス通信デバイス。
［Ｃ１５］
前記命令が、
複数のチャネル情報要求を受信することと、
前記チャネル情報要求の各々についてのチャネル情報を判断することと、
前記チャネル情報を送ることと
を行うようにさらに実行可能である、Ｃ１４に記載のワイヤレス通信デバイス。
［Ｃ１６］
前記命令が、送信可（ＣＴＳ）信号を受信し、信号を送信する前に所定の時間量を待つようにさらに実行可能である、Ｃ１４に記載のワイヤレス通信デバイス。
［Ｃ１７］
前記データが、式

に従って空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の特異値であり、Ｈ _ck が前記ワイヤレス通信デバイスｃについてのチャネルであり、Ｎ _ssck がグループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、

がＨ _ck の左特異ベクトルを含み、上付き文字 ^H が共役転置を示す、Ｃ１４に記載のワイヤレス通信デバイス。
［Ｃ１８］
前記データが、式

に従って空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の左特異ベクトルを含み、Ｈ _ck が前記ワイヤレス通信デバイスｃについてのチャネルであり、上付き文字 ^H が共役転置を示す、Ｃ１４に記載のワイヤレス通信デバイス。
［Ｃ１９］
基地局がワイヤレス通信デバイスの複数のグループと通信するための方法であって、
ワイヤレス通信デバイスの数を判断することと、
前記数のワイヤレス通信デバイスをグループに分割することと、
各グループについてのプリコーディング行列を判断することと、
各グループについての前記プリコーディング行列を使用して、ビームフォーミングされた信号を各グループに送信することと
を備える、方法。
［Ｃ２０］
各グループについての前記プリコーディング行列を判断することが、プリアンブルの全方向性部分をビームフォーミングするために実行される、Ｃ１９に記載の方法。
［Ｃ２１］
チャネル情報を受信することをさらに備える、Ｃ１９に記載の方法。
［Ｃ２２］
各グループについての前記プリコーディング行列を判断することが、
現在グループについてのグループチャネルを判断することと、
コンプリメントグループチャネルを判断することと、
コンプリメントグループチャネル零空間を判断することと、
前記現在グループ中の各ワイヤレス通信デバイスについてのクライアントチャネルを判断することと、
各ワイヤレス通信デバイスについての前記クライアントチャネルと前記コンプリメントグループチャネル零空間とに基づいて前記現在グループについてのプリコーディング行列を判断することと
を備える、Ｃ１９に記載の方法。
［Ｃ２３］
前記コンプリメントグループチャネル零空間を判断することが、式

に従って達成され、

が前記コンプリメントグループチャネルであり、Ｕ’が

の左特異ベクトルを含み、Ｓ’が

の特異値であり、Ｖ’が

の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、前記コンプリメントグループチャネル零空間Ｖ _n がＶ’の最後のＮ _tx −（Ｎ _rxt −Ｎ _rxk ）個の列を備える、ここで、Ｎ _tx が基地局送信機の数であり、Ｎ _rxt がワイヤレス通信デバイス受信機の総数であり、Ｎ _rxk がグループｋ中の受信機の総数である、Ｃ２２に記載の方法。
［Ｃ２４］
前記現在グループについての前記プリコーディング行列を判断することが、式［Ｕ _m ，Ｓ _m ，Ｖ _m ］＝ｓｖｄ（Ｈ _mk Ｖ _n ）と式

とに従って達成される、ここで、Ｈ _mk が前記クライアントチャネルであり、Ｖ _n が前記コンプリメントグループチャネル零空間であり、Ｕ _m がＨ _mk Ｖ _n の左特異ベクトルを含み、Ｓ _m がＨ _mk Ｖ _n の特異値であり、Ｖ _m がＨ _mk Ｖ _n の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、Ｗ _k がグループｋについての前記プリコーディング行列であり、ｍが指数である、Ｃ２２に記載の方法。
［Ｃ２５］
前記現在グループについての前記プリコーディング行列を判断することが、式［Ｕ _m ，Ｓ _m ，Ｖ _m ］＝ｓｖｄ（Ｈ _mk Ｖ _n ）と、式Ｚ（：，（ｍ−１）Ｎ _ssmk ＋１：ｍ＊Ｎ _ssmk ）＝Ｖ _m （：，１：Ｎ _ssmk ）Ｓ _m （１：Ｎ _ssmk ，１：Ｎ _ssmk ）と式

とに従って達成される、ここで、Ｈ _mk が前記クライアントチャネルであり、Ｖ _n が前記コンプリメントグループチャネル零空間であり、Ｕ _m がＨ _mk Ｖ _n の左特異ベクトルを含み、Ｓ _m がＨ _mk Ｖ _n の特異値であり、Ｖ _m がＨ _mk Ｖ _n の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、Ｎ _ssmk がグループｋ中のワイヤレス通信デバイスｍの空間ストリームの数であり、Ｚが、選択された固有モードを備える行列であり、上付き文字 ^H が共役転置を示し、Ｉが単位行列であり、ＳＮＲ _k が前記グループｋについてのダウンリンクにおける平均信号対雑音比（ＳＮＲ）の推定値であり、Ｗ _km が前記プリコーディング行列である、Ｃ２２に記載の方法。
［Ｃ２６］
前記現在グループについての前記プリコーディング行列を判断することが、式［Ｕ _m ，Ｓ _m ，Ｖ _m ］＝ｓｖｄ（Ｈ _mk Ｖ _n ）と、式Ｄ _m ＝Ｖ _m （：，１：Ｎ _ssmk ）Ｓ _m （１：Ｎ _ssmk ，１：Ｎ _ssmk ）と、式

と、式［Ｕ _mz ，Ｓ _mz ，Ｖ _mz ］＝ｓｖｄ（Ｚ）と、式

と、式

とに従って達成される、ここで、Ｈ _mk が前記クライアントチャネルであり、Ｖ _n が前記コンプリメントグループチャネル零空間であり、Ｕ _m がＨ _mk Ｖ _n の左特異ベクトルを含み、Ｓ _m がＨ _mk Ｖ _n の特異値であり、Ｖ _m がＨ _mk Ｖ _n の右特異ベクトルを含み、ｓｖｄ（）が特異値分解関数であり、Ｎ _ssmk がグループｋ中のワイヤレス通信デバイスｍの空間ストリームの数であり、Ｄ _m が前記ワイヤレス通信デバイスｍについてのステアリングベクトルであり、Ｚが、前記ワイヤレス通信デバイスｍ以外の前記グループｋ中のすべてのワイヤレス通信デバイスへのステアリングベクトルの行列であり、上付き文字 ^H が共役転置を示し、Ｎ _ck が前記グループｋ中のワイヤレス通信デバイスの数であり、Ｕ _mz がＺの左特異ベクトルを含み、Ｓ _mz がＺの特異値であり、Ｖ _mz がＺの右特異ベクトルを含み、Ｕが

の左特異ベクトルを含み、Ｓが

の特異値であり、Ｖが

の右特異ベクトルを含み、Ｎ _ssk が前記グループｋについての空間ストリームの数であり、

がＮ _ssmk 個の行および列をもつ単位行列であり、ＳＮＲ _k が前記グループｋについてのダウンリンクにおける平均信号対雑音比（ＳＮＲ）の推定値であり、Ｗ _km が前記プリコーディング行列である、Ｃ２２に記載の方法。
［Ｃ２７］
現在グループについての前記プリコーディング行列がプリアンブルの第１の部分に適用され、前記方法が、前記プリアンブルの第２の部分に適用される前記現在グループについての第２のプリコーディング行列を判断することをさらに備える、Ｃ１９に記載の方法。
［Ｃ２８］
異なるチャネル状態情報要求のために少なくとも１つの共通アンテナを使用して、複数のチャネル状態情報要求を同じワイヤレス通信デバイスに送ることと、
前記同じワイヤレス通信デバイスから複数のチャネル状態情報メッセージを受信することと、
前記複数のチャネル状態情報メッセージを組み合わせることと
をさらに備える、Ｃ１９に記載の方法。
［Ｃ２９］
メディアアクセス制御保護を使用することをさらに備える、Ｃ１９に記載の方法。
［Ｃ３０］
前記現在グループについての前記プリコーディング行列を判断することが、Ｈ _ck を

に設定することによって達成される、ここで、Ｈ _ck がグループｋ中のワイヤレス通信デバイスｃについてのチャネルであり、

が前記ワイヤレス通信デバイスｃについてのビームフォーミング行列であり、Ｎ _ssck が前記グループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、上付き文字 ^H が共役転置を示す、Ｃ２２に記載の方法。
［Ｃ３１］
前記現在グループについての前記プリコーディング行列を判断することが、Ｈ _ck を

に設定することによって達成される、ここで、Ｈ _ck がグループｋ中のワイヤレス通信デバイスｃについてのチャネルであり、

が前記ワイヤレス通信デバイスｃについてのビームフォーミング行列であり、

が前記ワイヤレス通信デバイスｃについての特異値であり、Ｎ _ssck が前記グループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、上付き文字 ^H が共役転置を示す、Ｃ２２に記載の方法。
［Ｃ３２］
ワイヤレス通信デバイスがグループ信号を受信するための方法であって、
２つ以上のワイヤレス通信デバイスについての情報を含むグループ信号を受信することと、
空間フィルタ処理を使用して、前記グループ信号から前記ワイヤレス通信デバイスについてのデータを復元することと
を備える、方法。
［Ｃ３３］
複数のチャネル情報要求を受信することと、
前記チャネル情報要求の各々についてのチャネル情報を判断することと、
前記チャネル情報を送ることと
をさらに備える、Ｃ３２に記載の方法。
［Ｃ３４］
送信可（ＣＴＳ）信号を受信することと、信号を送信する前に所定の時間量を待つことをさらに備える、Ｃ３２に記載の方法。
［Ｃ３５］
前記データが、式

に従って空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の特異値であり、Ｈ _ck が前記ワイヤレス通信デバイスｃについてのチャネルであり、Ｎ _ssck がグループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、

がＨ _ck の左特異ベクトルを含み、上付き文字 ^H が共役転置を示す、Ｃ３２に記載の方法。
［Ｃ３６］
前記データが、式

に従って空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の左特異ベクトルを含み、上付き文字 ^H が共役転置を示す、Ｃ３２に記載の方法。
［Ｃ３７］
命令をその上に有する非一時的有形のコンピュータ可読媒体を備える、ワイヤレス通信デバイスの複数のグループと通信するためのコンピュータプログラム製品であって、前記命令が、
基地局にワイヤレス通信デバイスの数を判断させるためのコードと、
前記基地局に前記数のワイヤレス通信デバイスをグループに分割させるためのコードと、
前記基地局に各グループについてのプリコーディング行列を判断させるためのコードと、
前記基地局に、各グループについての前記プリコーディング行列を使用して、ビームフォーミングされた信号を各グループに送信させるためのコードと
を備える、コンピュータプログラム製品。
［Ｃ３８］
各グループについての前記プリコーディング行列を判断することが、プリアンブルの全方向性部分をビームフォーミングするために実行される、Ｃ３７に記載のコンピュータプログラム製品。
［Ｃ３９］
各グループについての前記プリコーディング行列を判断することが、
現在グループについてのグループチャネルを判断することと、
コンプリメントグループチャネルを判断することと、
コンプリメントグループチャネル零空間を判断することと、
前記現在グループ中の各ワイヤレス通信デバイスについてのクライアントチャネルを判断することと、
各ワイヤレス通信デバイスについての前記クライアントチャネルと前記コンプリメントグループチャネル零空間とに基づいて前記現在グループについてのプリコーディング行列を判断することと
を備える、Ｃ３７に記載のコンピュータプログラム製品。
［Ｃ４０］
前記命令が、
前記基地局に、異なるチャネル状態情報要求のために少なくとも１つの共通アンテナを使用して、複数のチャネル状態情報要求を同じワイヤレス通信デバイスに送信させるためのコードと、
前記基地局に、前記同じワイヤレス通信デバイスから複数のチャネル状態情報メッセージを受信させるためのコードと、
前記基地局に、前記複数のチャネル状態情報メッセージを組み合わさせるためのコードと
をさらに備える、Ｃ３７に記載のコンピュータプログラム製品。
［Ｃ４１］
命令をその上に有する非一時的有形コンピュータ可読媒体を備える、グループ信号を受信するためのコンピュータプログラム製品であって、前記命令が、
ワイヤレス通信デバイスに、２つ以上のワイヤレス通信デバイスについての情報を含むグループ信号を受信させるためのコードと、
前記ワイヤレス通信デバイスに、空間フィルタ処理を使用して、前記グループ信号から前記ワイヤレス通信デバイスについてのデータを復元させるためのコードとを備える、コンピュータプログラム製品。
［Ｃ４２］
前記データが、式

に従った空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の特異値であり、Ｈ _ck が前記ワイヤレス通信デバイスｃについてのチャネルであり、Ｎ _ssck がグループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、

がＨ _ck の左特異ベクトルを含み、上付き文字 ^H が共役転置を示す、Ｃ４１に記載のコンピュータプログラム製品。
［Ｃ４３］
前記データが、式

に従って空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の左特異ベクトルを含み、上付き文字 ^H が共役転置を示す、Ｃ４１に記載のコンピュータプログラム製品。
［Ｃ４４］
ワイヤレス通信デバイスの複数のグループと通信するための装置であって、
ワイヤレス通信デバイスの数を判断するための手段と、
前記数のワイヤレス通信デバイスをグループに分割するための手段と、
各グループについてのプリコーディング行列を判断するための手段と、
各グループについての前記プリコーディング行列を使用して、ビームフォーミングされた信号を各グループに送信するための手段と
を備える、装置。
［Ｃ４５］
各グループについての前記プリコーディング行列を判断することが、プリアンブルの全方向性部分をビームフォーミングするために実行される、Ｃ４４に記載の装置。
［Ｃ４６］
各グループについての前記プリコーディング行列を判断することが、
現在グループについてのグループチャネルを判断することと、
コンプリメントグループチャネルを判断することと、
コンプリメントグループチャネル零空間を判断することと、
前記現在グループ中の各ワイヤレス通信デバイスについてのクライアントチャネルを判断することと、
各ワイヤレス通信デバイスについての前記クライアントチャネルと前記コンプリメントグループチャネル零空間とに基づいて前記現在グループについてのプリコーディング行列を判断することと
を備える、Ｃ４４に記載の装置。
［Ｃ４７］
異なるチャネル状態情報要求のために少なくとも１つの共通アンテナを使用して、複数のチャネル状態情報要求を同じワイヤレス通信デバイスに送信するための手段と、
前記同じワイヤレス通信デバイスから複数のチャネル状態情報メッセージを受信するための手段と、
前記複数のチャネル状態情報メッセージを組み合わせるための手段と
をさらに備える、Ｃ４４に記載の装置。
［Ｃ４８］
グループ信号を受信するための装置であって、
２つ以上のワイヤレス通信デバイスについての情報を含むグループ信号を受信するための手段と、
空間フィルタ処理を使用して、前記グループ信号から前記ワイヤレス通信デバイスについてのデータを復元するための手段と
を備える、装置。
［Ｃ４９］
前記データが、式

に従った空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の特異値であり、Ｈ _ck が前記ワイヤレス通信デバイスｃについてのチャネルであり、Ｎ _ssck がグループｋ中の前記ワイヤレス通信デバイスｃについての空間ストリームの数であり、

がＨ _ck の左特異ベクトルを含み、上付き文字 ^H が共役転置を示す、Ｃ４８に記載の装置。
［Ｃ５０］
前記データが、式

に従って空間フィルタ処理を使用して復元される、ここで、Ｕ _c が、前記ワイヤレス通信デバイスｍ＝ｃについてのＨ _mk Ｖ _n の左特異ベクトルを含むＵ _m であり、Ｈ _mk がクライアントチャネルであり、Ｖ _n がコンプリメントグループチャネル零空間であり、

がＨ _ck の左特異ベクトルを含み、Ｈ _ck が前記ワイヤレス通信デバイスｃについてのチャネルであり、上付き文字 ^H が共役転置を示す、Ｃ４８に記載の装置。 [00216] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the operation and details of the systems, methods, and apparatus described herein without departing from the scope of the claims.
Hereinafter, the invention described in the scope of claims of the present application will be appended.
[C1]
A processor;
Memory in electronic communication with the processor;
Instructions stored in the memory;
A base station for communicating with a plurality of groups of wireless communication devices, the instructions comprising:
Determining the number of wireless communication devices;
Dividing the number of wireless communication devices into groups;
Determining a precoding matrix for each group;
Using the precoding matrix for each group to transmit a beamformed signal to each group;
A base station that is feasible to do.
[C2]
The base station of C1, wherein determining the precoding matrix for each group is performed for beamforming an omnidirectional portion of a preamble.
[C3]
The base station according to C1, wherein the instructions are further executable to receive channel information.
[C4]
Determining the precoding matrix for each group;
Determining the group channel for the current group,
Determining the complement group channel;
Determining a complement group channel null space;
Determining a client channel for each wireless communication device in the current group;
Determining a precoding matrix for the current group based on the client channel and the complement group channel null space for each wireless communication device;
A base station according to C1, comprising:
[C5]
Determining the complement group channel null space has the formula

Achieved according to

Is the complement group channel and U ′ is

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , The base station according to _C4 , wherein N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k.
[C6]
Determining the precoding matrix for the current group is represented by the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk Is the singular value of V _n , V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, W _k is the precoding matrix for group k, and m is the exponent The base station according to C4.
[C7]
Determining the precoding matrix for the current group consists of the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation Z (:, (m−1) N _ssmk +1: m * N _ssmk ) = V _m (:, 1: N _ssmk ) S _m (1: N _ssmk , 1: N _ssmk ) and formula

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. Yes, Z is a matrix with the selected eigenmode, superscript ^H indicates the conjugate transpose, I is the identity matrix, and SNR _k is the average signal-to-noise ratio in the downlink for group k ( The base station according to C4, which is an estimated value of SNR) and W _km is the precoding matrix.
[C8]
Determining the precoding matrix for the current group consists of the expression [U _m , S _m , V _m ] = svd (H _mk V _n ) and the expression D _m = V _m (:, 1: N _ssmk ). S _m (1: N _ssmk , 1: N _ssmk ) and the formula

And the expression

And the expression

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. D _m is a steering vector for the wireless communication device m, Z is a matrix of steering vectors of all wireless communication devices in the group k other than the wireless communication device m, and the superscript ^H is N _ck is the number of wireless communication devices in group k, U _mz contains the left singular vector of Z , and S _mz is the singular value of Z V _mz contains the right singular vector of Z and U is

Where S is the left singular vector

Singular value of V

N _ssk is the number of spatial streams for the group k,

Is an identity matrix with N _ssmk rows and columns, SNR _k is an estimate of the average signal-to-noise ratio (SNR) in the downlink for the group k, and W _km is the precoding matrix, The base station according to C4.
[C9]
Such that the precoding matrix for a current group is applied to a first part of a preamble, and the instructions determine a second precoding matrix for the current group applied to a second part of the preamble. The base station according to C1, further executable.
[C10]
The instruction is
Sending multiple channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
Receiving a plurality of channel state information messages from the same wireless communication device;
Combining the plurality of channel state information messages;
The base station according to C1, further executable to perform.
[C11]
The base station according to C1, wherein the instructions are further executable to use media access control protection.
[C12]
Wherein it is possible to determine the precoding matrix for the current group, the H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is the beamforming matrix for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H indicates conjugate transpose. base station.
[C13]
Wherein it is possible to determine the precoding matrix for the current group, the H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is a beamforming matrix for the wireless communication device c;

Is a singular value for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H indicates a conjugate transpose. Bureau.
[C14]
A processor;
Memory in electronic communication with the processor;
Instructions stored in the memory;
A wireless communication device for receiving a group signal, the instructions comprising:
Receiving a group signal including information about two or more wireless communication devices;
Reconstructing data about the wireless communication device from the group signal using spatial filtering;
A wireless communication device that is feasible to do.
[C15]
The instruction is
Receiving multiple channel information requests;
Determining channel information for each of the channel information requests;
Sending the channel information;
The wireless communication device of C14, further executable to do.
[C16]
The wireless communication device of C14, wherein the instructions are further executable to receive a transmit ready (CTS) signal and wait for a predetermined amount of time before transmitting the signal.
[C17]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for the wireless communication device m = c , and H _mk is the client channel , V _n is the complement group channel null space,

There are specific values of H _ck, a channel H _ck is about the wireless communication device c, the number of spatial streams N _SSCK is for the wireless communication device c in group k,

There comprises a left singular vectors of H _ck, superscript ^H indicates conjugate transpose, a wireless communication device according to C14.
[C18]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for the wireless communication device m = c , and H _mk is the client channel , V _n is the complement group channel null space,

There comprises a left singular vectors of H _ck, a channel H _ck is about the wireless communication device c, the superscript ^H indicates conjugate transpose, a wireless communication device according to C14.
[C19]
A method for a base station to communicate with multiple groups of wireless communication devices, comprising:
Determining the number of wireless communication devices;
Dividing the number of wireless communication devices into groups;
Determining a precoding matrix for each group;
Using the precoding matrix for each group to transmit a beamformed signal to each group;
A method comprising:
[C20]
The method of C19, wherein determining the precoding matrix for each group is performed for beamforming an omnidirectional portion of a preamble.
[C21]
The method of C19, further comprising receiving channel information.
[C22]
Determining the precoding matrix for each group;
Determining the group channel for the current group,
Determining the complement group channel;
Determining a complement group channel null space;
Determining a client channel for each wireless communication device in the current group;
Determining a precoding matrix for the current group based on the client channel and the complement group channel null space for each wireless communication device;
The method according to C19, comprising:
[C23]
Determining the complement group channel null space has the formula

Achieved according to

Is the complement group channel and U ′ is

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k.
[C24]
Determining the precoding matrix for the current group is represented by the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk Is the singular value of V _n , V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, W _k is the precoding matrix for group k, and m is the exponent The method according to C22, wherein
[C25]
Determining the precoding matrix for the current group consists of the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation Z (:, (m−1) N _ssmk +1: m * N _ssmk ) = V _m (:, 1: N _ssmk ) S _m (1: N _ssmk , 1: N _ssmk ) and formula

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. Yes, Z is a matrix with the selected eigenmode, superscript ^H indicates the conjugate transpose, I is the identity matrix, and SNR _k is the average signal-to-noise ratio in the downlink for group k ( The method according to C22, which is an estimate of (SNR) and W _km is the precoding matrix.
[C26]
Determining the precoding matrix for the current group consists of the expression [U _m , S _m , V _m ] = svd (H _mk V _n ) and the expression D _m = V _m (:, 1: N _ssmk ). S _m (1: N _ssmk , 1: N _ssmk ) and the formula

And the formula [U _mz , S _mz , V _mz ] = svd (Z)

And the expression

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. D _m is a steering vector for the wireless communication device m, Z is a matrix of steering vectors to all wireless communication devices in the group k other than the wireless communication device m, and the superscript ^H Denotes conjugate transpose, N _ck is the number of wireless communication devices in group k, U _mz contains the left singular vector of Z , and S _mz is the singular value of Z V _mz contains the right singular vector of Z and U is

Where S is the left singular vector

Singular value of V

N _ssk is the number of spatial streams for the group k,

Is an identity matrix with N _ssmk rows and columns, SNR _k is an estimate of the average signal-to-noise ratio (SNR) in the downlink for the group k, and W _km is the precoding matrix, The method according to C22.
[C27]
The precoding matrix for a current group is applied to a first part of a preamble, and the method determines a second precoding matrix for the current group applied to a second part of the preamble. The method of C19, further comprising.
[C28]
Sending multiple channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
Receiving a plurality of channel state information messages from the same wireless communication device;
Combining the plurality of channel state information messages;
The method of C19, further comprising:
[C29]
The method of C19, further comprising using media access control protection.
[C30]
Wherein it is possible to determine the precoding matrix for the current group, the H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is the beamforming matrix for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H indicates conjugate transpose. Method.
[C31]
Wherein it is possible to determine the precoding matrix for the current group, the H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is a beamforming matrix for the wireless communication device c;

The method of C22, wherein is a singular value for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H indicates a conjugate transpose .
[C32]
A method for a wireless communication device to receive a group signal, comprising:
Receiving a group signal including information about two or more wireless communication devices;
Reconstructing data about the wireless communication device from the group signal using spatial filtering;
A method comprising:
[C33]
Receiving multiple channel information requests;
Determining channel information for each of the channel information requests;
Sending the channel information;
The method of C32, further comprising:
[C34]
The method of C32, further comprising receiving a transmit ready (CTS) signal and waiting for a predetermined amount of time before transmitting the signal.
[C35]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for the wireless communication device m = c , and H _mk is the client channel , V _n is the complement group channel null space,

There are specific values of H _ck, a channel H _ck is about the wireless communication device c, the number of spatial streams N _SSCK is for the wireless communication device c in group k,

There comprises a left singular vectors of H _ck, showing the superscript ^H is the conjugate transpose, A method according to C32.
[C36]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for the wireless communication device m = c , and H _mk is the client channel , V _n is the complement group channel null space,

There comprises a left singular vectors of H _ck, showing the superscript ^H is the conjugate transpose, A method according to C32.
[C37]
A computer program product for communicating with a plurality of groups of wireless communication devices comprising a non-transitory tangible computer readable medium having instructions thereon, the instructions comprising:
A code for causing the base station to determine the number of wireless communication devices;
A code for causing the base station to divide the number of wireless communication devices into groups;
A code for causing the base station to determine a precoding matrix for each group;
A code for causing the base station to transmit a beamformed signal to each group using the precoding matrix for each group;
A computer program product comprising:
[C38]
The computer program product of C37, wherein determining the precoding matrix for each group is performed to beamform an omnidirectional portion of a preamble.
[C39]
Determining the precoding matrix for each group;
Determining the group channel for the current group,
Determining the complement group channel;
Determining a complement group channel null space;
Determining a client channel for each wireless communication device in the current group;
Determining a precoding matrix for the current group based on the client channel and the complement group channel null space for each wireless communication device;
A computer program product according to C37, comprising:
[C40]
The instruction is
A code for causing the base station to transmit a plurality of channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
A code for causing the base station to receive a plurality of channel state information messages from the same wireless communication device;
A code for causing the base station to combine the plurality of channel state information messages;
The computer program product according to C37, further comprising:
[C41]
A computer program product for receiving a group signal comprising a non-transitory tangible computer readable medium having instructions thereon, the instructions comprising:
Code for causing a wireless communication device to receive a group signal including information about two or more wireless communication devices;
A computer program product comprising: code for causing the wireless communication device to recover data about the wireless communication device from the group signal using spatial filtering.
[C42]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for said wireless communication device m = c , and H _mk is the client channel V _n is the complement group channel null space,

There are specific values of H _ck, a channel H _ck is about the wireless communication device c, the number of spatial streams N _SSCK is for the wireless communication device c in group k,

There comprises a left singular vectors of H _ck, superscript ^H indicates conjugate transpose, computer program product according to C41.
[C43]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for the wireless communication device m = c , and H _mk is the client channel , V _n is the complement group channel null space,

There comprises a left singular vectors of H _ck, superscript ^H indicates conjugate transpose, computer program product according to C41.
[C44]
An apparatus for communicating with a plurality of groups of wireless communication devices, comprising:
Means for determining the number of wireless communication devices;
Means for dividing the number of wireless communication devices into groups;
Means for determining a precoding matrix for each group;
Means for transmitting a beamformed signal to each group using the precoding matrix for each group;
An apparatus comprising:
[C45]
The apparatus of C44, wherein determining the precoding matrix for each group is performed to beamform an omnidirectional portion of a preamble.
[C46]
Determining the precoding matrix for each group;
Determining the group channel for the current group,
Determining the complement group channel;
Determining a complement group channel null space;
Determining a client channel for each wireless communication device in the current group;
Determining a precoding matrix for the current group based on the client channel and the complement group channel null space for each wireless communication device;
The apparatus of C44, comprising:
[C47]
Means for transmitting a plurality of channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
Means for receiving a plurality of channel state information messages from the same wireless communication device;
Means for combining the plurality of channel state information messages;
The apparatus of C44, further comprising:
[C48]
A device for receiving a group signal,
Means for receiving a group signal including information about two or more wireless communication devices;
Means for recovering data about the wireless communication device from the group signal using spatial filtering;
An apparatus comprising:
[C49]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for said wireless communication device m = c , and H _mk is the client channel V _n is the complement group channel null space,

There are specific values of H _ck, a channel H _ck is about the wireless communication device c, the number of spatial streams N _SSCK is for the wireless communication device c in group k,

There comprises a left singular vectors of H _ck, showing the superscript ^H is the conjugate transpose, according to C48.
[C50]
The data is an expression

And U _c is U _m containing the left singular vector of H _mk V _n for the wireless communication device m = c , and H _mk is the client channel , V _n is the complement group channel null space,

There comprises a left singular vectors of H _ck, a channel H _ck is about the wireless communication device c, it shows the superscript ^H is the conjugate transpose, according to C48.

Claims (28)

A processor;
Memory in electronic communication with the processor;
A base station for communicating with a plurality of groups of wireless communication devices comprising: instructions stored in the memory, wherein the instructions are
Determining a precoding matrix for each group, wherein determining the precoding matrix for each group includes determining a complement group channel that is a channel of all groups other than the current group. Determining a complement group channel null space; and determining a precoding matrix for the current group based on a client channel and the complement group channel null space for each wireless communication device of the current group; And the precoding matrix for the current group is applied to a first part of a preamble,
Determining a second precoding matrix for the current group applied to a second portion of the preamble;
Using said precoding matrix for each group, Ri executable der to perform and transmitting the beamformed signals in each group,
Determining the complement group channel null space has the formula

Achieved according to

The complement group channel, where U ′

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , A base station where N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k .   The base station according to claim 1, wherein determining the precoding matrix for each group is performed for beamforming an omnidirectional portion of the preamble.   The base station of claim 1, wherein the instructions are further executable to receive channel information. Determining the precoding matrix for each group;
Determining a group channel for the current group;
Determining the client channel for each wireless communication device in the current group;
The base station according to claim 1, further comprising: Determining the precoding matrix for the current group is represented by the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk Is the singular value of V _n , V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, W _k is the precoding matrix for group k, and m is the exponent The base station according to claim 4, wherein Determining the precoding matrix for the current group consists of the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation Z (:, (m−1) N _ssmk +1: m * N _ssmk ) = V _m (:, 1: N _ssmk ) S _m (1: N _ssmk , 1: N _ssmk ) and formula

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. Yes, Z is a matrix with the selected eigenmode, superscript ^H indicates the conjugate transpose, I is the identity matrix, and SNR _k is the average signal-to-noise ratio in the downlink for group k ( 5. The base station according to claim 4, wherein the estimated value is SNR) and W _km is the precoding matrix. Determining the precoding matrix for the current group consists of the expression [U _m , S _m , V _m ] = svd (H _mk V _n ) and the expression D _m = V _m (:, 1: N _ssmk ). S _m (1: N _ssmk , 1: N _ssmk ) and the formula

And the formula [U _mz , S _mz , V _mz ] = svd (Z)

And the expression

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. D _m is a steering vector for the wireless communication device m, Z is a matrix of steering vectors to all wireless communication devices in the group k other than the wireless communication device m, and the superscript ^H Denotes conjugate transpose, N _ck is the number of wireless communication devices in group k, U _mz contains the left singular vector of Z, and S _mz is the singular value of Z V _mz contains the right singular vector of Z and U is

Where S is the left singular vector

Singular value of V

N _ssk is the number of spatial streams for the group k,

Is an identity matrix with N _ssmk rows and columns, SNR _k is an estimate of the average signal-to-noise ratio (SNR) in the downlink for the group k, and W _km is the precoding matrix, The base station according to claim 4. Determining the precoding matrix for the current group determines H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is the beamforming matrix containing the right singular vector of H _ck for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H is conjugate The base station according to claim 4, which indicates transposition. Determining the precoding matrix for the current group determines H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is a beamforming matrix comprising the right singular vector of _Hck for the wireless communication device c;

Is the singular value of H _ck for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H indicates conjugate transpose. 4. A base station according to 4. A method for a base station to communicate with multiple groups of wireless communication devices, comprising:
Determining a precoding matrix for each group, wherein determining the precoding matrix for each group includes determining a complement group channel that is a channel of all groups other than the current group. Determining a complement group channel null space; and determining a precoding matrix for the current group based on a client channel and the complement group channel null space for each wireless communication device of the current group; And the precoding matrix for the current group is applied to a first part of a preamble,
And to determine the second precoding matrix for the current group that will be applied to the second portion of the preamble,
Using the precoding matrix for each group to transmit a beamformed signal to each group;
Determining the complement group channel null space has the formula

Achieved according to

Is the complement group channel and U ′ is

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k . The method of claim 10 , wherein determining the precoding matrix for each group is performed to beamform an omnidirectional portion of the preamble. The method of claim 10 , further comprising receiving channel information. Determining the precoding matrix for each group;
Determining a group channel for the current group;
Determining the client channel for each wireless communication device in the current group;
The method of claim 10 , further comprising: Determining the precoding matrix for the current group is represented by the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk Is the singular value of V _n , V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, W _k is the precoding matrix for group k, and m is the exponent 14. The method of claim 13 , wherein Determining the precoding matrix for the current group consists of the equation [U _m , S _m , V _m ] = svd (H _mk V _n ) and the equation Z (:, (m−1) N _ssmk +1: m * N _ssmk ) = V _m (:, 1: N _ssmk ) S _m (1: N _ssmk , 1: N _ssmk ) and formula

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. Yes, Z is a matrix with the selected eigenmode, superscript ^H indicates the conjugate transpose, I is the identity matrix, and SNR _k is the average signal-to-noise ratio in the downlink for group k ( The method of claim 13 , wherein the estimated value is SNR) and W _km is the precoding matrix. Determining the precoding matrix for the current group consists of the expression [U _m , S _m , V _m ] = svd (H _mk V _n ) and the expression D _m = V _m (:, 1: N _ssmk ). S _m (1: N _ssmk , 1: N _ssmk ) and the formula

And the formula [U _mz , S _mz , V _mz ] = svd (Z)

And the expression

Where H _mk is the client channel, V _n is the complement group channel null space, U _m contains the left singular vector of H _mk V _n , and S _m is H _mk V _{n is} the singular value, V _m contains the right singular vector of H _mk V _n , svd () is the singular value decomposition function, and N _ssmk is the number of spatial streams of the wireless communication device m in group k. D _m is a steering vector for the wireless communication device m, Z is a matrix of steering vectors to all wireless communication devices in the group k other than the wireless communication device m, and the superscript ^H Denotes conjugate transpose, N _ck is the number of wireless communication devices in group k, U _mz contains the left singular vector of Z, and S _mz is the singular value of Z V _mz contains the right singular vector of Z and U is

Where S is the left singular vector

Singular value of V

N _ssk is the number of spatial streams for the group k,

Is an identity matrix with N _ssmk rows and columns, SNR _k is an estimate of the average signal-to-noise ratio (SNR) in the downlink for the group k, and W _km is the precoding matrix, The method of claim 13 . Sending multiple channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
Receiving a plurality of channel state information messages from the same wireless communication device;
The method of claim 10 , further comprising combining the plurality of channel state information messages. Determining the precoding matrix for the current group determines H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is the beamforming matrix containing the right singular vector of H _ck for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H is conjugate The method of claim 13 , wherein transposition is indicated. Determining the precoding matrix for the current group determines H _ck

Where H _ck is the channel for wireless communication device c in group k, and

Is a beamforming matrix comprising the right singular vector of _Hck for the wireless communication device c;

Is the singular value of H _ck for the wireless communication device c, N _ssck is the number of spatial streams for the wireless communication device c in the group k, and the superscript ^H indicates conjugate transpose. 14. The method according to 13 . A computer readable storage medium for communicating with a plurality of groups of wireless communication devices having instructions stored therein, the instructions comprising:
A code for causing the base station to determine a precoding matrix for each group, and determining the precoding matrix for each group is a complement group channel that is a channel of all groups other than the current group Determining a complement group channel null space and a precoding matrix for the current group based on a client channel and the complement group channel null space for each wireless communication device of the current group And the precoding matrix for the current group is applied to a first part of a preamble,
A code for causing the base station to determine a second precoding matrix for the current group applied to a second portion of the preamble;
A code for causing the base station to transmit a beamformed signal to each group using the precoding matrix for each group;
Determining the complement group channel null space has the formula

Achieved according to

Is the complement group channel and U ′ is

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k.
Computer-readable storage medium. 21. The computer readable storage medium of claim 20 , wherein determining the precoding matrix for each group is performed for beamforming an omnidirectional portion of the preamble. Determining the precoding matrix for each group;
Determining a group channel for the current group;
Determining the client channel for each wireless communication device in the current group;
The computer-readable storage medium of claim 20 , further comprising: The instruction is
A code for causing the base station to transmit a plurality of channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
A code for causing the base station to receive a plurality of channel state information messages from the same wireless communication device;
Wherein the base station further comprises code for causing a combination of the plurality of channel state information message, computer-readable storage medium of claim 20. An apparatus for communicating with a plurality of groups of wireless communication devices, comprising:
Means for determining a complement group channel that is a channel of all groups other than the current group; means for determining a complement group channel null space; and a client channel for each wireless communication device of the current group; Means for determining a precoding matrix for the current group based on the complement group channel null space, wherein the means for determining a precoding matrix for each group, wherein the current The precoding matrix for the group is applied to the first part of the preamble;
Means for determining a second precoding matrix for the current group applied to a second portion of the preamble;
Means for transmitting a beamformed signal to each group using the precoding matrix for each group;
Determining the complement group channel null space has the formula

Achieved according to

Is the complement group channel and U ′ is

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k.
apparatus. 25. The apparatus of claim 24 , wherein determining the precoding matrix for each group is performed for beamforming an omnidirectional portion of the preamble. The means for determining the precoding matrix for each group comprises:
Means for determining a group channel for the current group;
Means for determining the client channel for each wireless communication device in the current group;
25. The apparatus of claim 24 , further comprising: Means for transmitting a plurality of channel state information requests to the same wireless communication device using at least one common antenna for different channel state information requests;
Means for receiving a plurality of channel state information messages from the same wireless communication device;
25. The apparatus of claim 24 , further comprising: means for combining the plurality of channel state information messages. A method for communicating with a plurality of groups of base stations and wireless communication devices in a system, comprising:
Determining a precoding matrix for each group, wherein determining the precoding matrix for each group includes determining a complement group channel that is a channel of all groups other than the current group. Determining a complement group channel null space; and determining a precoding matrix for the current group based on a client channel and the complement group channel null space for each wireless communication device of the current group; And the precoding matrix for the current group is applied to a first part of a preamble,
Determining a second precoding matrix for the current group applied to a second portion of the preamble;
Using the precoding matrix for each group to transmit a beamformed signal to each group;
Receiving a group signal including information about two or more wireless communication devices;
Using spatial filtering to recover data about a wireless communication device from the group signal;
Determining the complement group channel null space has the formula

Achieved according to

Is the complement group channel and U ′ is

And S 'is

Singular value of V '

Svd () is a singular value decomposition function, and the complement group channel null space V _n comprises the last N _tx − (N _rxt −N _rxk ) columns of V ′ , N _tx is the number of base station transmitters, N _rxt is the total number of wireless communication device receivers, and N _rxk is the total number of receivers in group k .

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